[HN Gopher] A VGA monitor may be easier to repair than you think
___________________________________________________________________
A VGA monitor may be easier to repair than you think
Author : watchdogtimer
Score : 99 points
Date : 2021-09-07 09:16 UTC (2 days ago)
(HTM) web link (www.cnx-software.com)
(TXT) w3m dump (www.cnx-software.com)
| goda90 wrote:
| I've got several broken electronics that I'd love to try to
| repair someday, but they don't have any screws and they are
| obscure enough to not have any tear-down guides to tell me if a
| heat gun would help. Cutting them open could just leave them
| unappealing to use, and thus I wasted my time.
| bluGill wrote:
| I like working on things that are broken: you break it such
| that you can't get it back together again, who cares, it was
| broken anyway. What I worry about are things that work but need
| maintenance - mess up the oil change an a good car and you
| destroy the car...
|
| In short, get in there are see what happens. Sometimes you will
| destroy something, but right now it is landfill material so you
| didn't lose anything. sometimes it is an easy fix.
| zbuf wrote:
| I feel old; I came here for a guide to repair a "VGA monitor" and
| instead got a flat panel.
| sysadmindotfail wrote:
| I am old. I did not even open the link until you mentioned it
| was an LCD. I was thinking: "Why would you repair a CRT?"
| tyingq wrote:
| Comes up fairly often as a nostalgia thing for old Macs,
| Kaypros, Compaqs, arcade games, and so on.
| ectopod wrote:
| Also, some home computer games from the 80s can be really
| hard to play with any extra latency so a CRT helps.
| bityard wrote:
| For most of the last 15 years, if you had an old CRT
| television or computer monitor, you had actually to pay
| someone just to get rid of it. Because of the lead
| shielding used in CRT tubes, they are considered hazardous
| waste. (Of course, most people were irresponsible or just
| didn't know any better and just chucked theirs into a
| dumpster.)
|
| But in the past few years, retro tech has become
| sufficiently popular due to certain YouTube channels that a
| CRT TV or monitor in good working condition can now command
| a worthwhile price.
| tailspin2019 wrote:
| > I was thinking: "Why would you repair a CRT?"
|
| Same here. And I didn't think I was _that_ old...
| deelowe wrote:
| Lots of older equipment require a CRT to function properly.
| caymanjim wrote:
| It's a VGA monitor. You may have expected a CRT rather than
| LCD, but that's a different confusion.
| zbuf wrote:
| Don't worry, I'm not confused...
| p1mrx wrote:
| LCD monitors only used VGA because customers didn't know enough
| to demand DVI. A pixel array is inherently digital, so it makes
| no sense to put DAC/ADC in the path.
| zbuf wrote:
| > customers didn't know enough to demand DVI
|
| Really, it was more that we didn't have DVI outputs.
|
| Its the smartest way to break the chicken-egg situation --
| for many (I'd wager the majority) the advantage of a flat
| panel at first was more about space saving then picture
| quality.
| p1mrx wrote:
| DVI output was easy; just buy a video card.
|
| The problem is, you can't add DVI to a VGA-only LCD
| monitor, and those things were everywhere.
| wiz21c wrote:
| FTA:
|
| > it was clear what the problem was with a swollen C812
| capacitor.
|
| > So no need to check anything with a multimeter or an
| oscilloscope, a visual inspection of the board could immediately
| detect the issue.
|
| I'm looking at the picture. I'm not in electronics and I can
| assure you it's absolutely not clear to me that this is the
| capacitor I'm looking for. So what should it look like ? I
| understand these things sometimes burn or swell but is it always
| visible ? And if not, what should I do to detect it ?
| opheliate wrote:
| As I understand it, as someone who is also not in electronics,
| the cross at the top of the other capacitors you can see is
| designed as a pressure release, it's a deliberate weakness in
| the structure of the capacitor so that if it fails, that's
| where it will burst. So it's very likely that if a cap fails,
| that's where any swelling will be visible. You can see the
| cross is distorted/swollen on the failed cap.
| tyingq wrote:
| Sounds like trolling (it's not), but some electrolytic
| capacitors have a fishy smell when they've leaked.
| gbil wrote:
| I'm an electronic engineer by education and have worked with
| boards many times as a hobby only though (outside of the
| university) and I can tell you I do see the capacitor being
| swollen just from the picture, you can see the ones below are
| in a normal state. Many times this is very very obvious but
| other times not in which case you need to remove each capacitor
| and measure its capacitance with the relevant (cheap) equipment
| jeroenhd wrote:
| I'm always wary if these guides. If you know what you're doing
| then yes, replacing a capacitor is a quick fix to give your
| hardware a new lease on life, but you can get seriously injured
| or even killed if you mishandled the open power supplies these
| devices often contain.
|
| This guide addresses the danger by saying you need to "wait for a
| while" without telling you what "a while" is (a minute? 5? an
| hour?) and how to spot the dangerous parts of the circuit board.
|
| Having said all that, I think a general education on how devices
| like these can be fixed (safely!) is something a lot educational
| facilities should offer. Repairing basic and often even more
| advanced electronics requires little more than replacement parts,
| a soldering iron and some practice, but people are quick to throw
| something out when it stops working. The assumption seems to be
| that things are too complex to repair these days, but in all
| likelihood dead devices just had some protective circuitry do its
| job and fail before frying the mail circuits.
| G3rn0ti wrote:
| Well, knowing capacitors to be a common culprit with broken
| monitors might inspire the non-electronics-savvy to go to a
| repair shop instead of shopping for a new monitor. And save
| money and the environment I might add.
| barbegal wrote:
| IEC 60335 and IEC 62368 state that the voltage across the
| capacitors must be below 34 V in 1 second after the input power
| is removed. Modern electronics are remarkably safe and I have
| never heard of anyone being shocked by power supply capacitors
| in the last decade. Of course cheap electronics sometimes
| aren't standards compliant and bleed resistors can conceivably
| fail hence the advice to wait a bit longer if you want real
| piece of mind and don't mind waiting.
| Waterluvian wrote:
| What do bleed resistors drain towards if the ground wire has
| been unplugged by unplugging the monitor?
| [deleted]
| amelius wrote:
| They don't bleed to ground. Even if the power-chord is
| disconnected, there still is a circuit between the resistor
| and the capacitor, and this is where the current runs.
| wongarsu wrote:
| It's just a resistor over the capacitor that slowly draws
| current from it. Little enough that it doesn't matter in
| normal operation, but enough to reasonably quickly
| discharge the capacitor to a safe level when power is
| removed.
| _fizz_buzz_ wrote:
| You should never discharge towards the ground wire. The
| resistor is simply across the two poles of the capacitor.
| HPsquared wrote:
| A charged capacitor has a surplus of electrons on one side,
| and a shortage on the other. A bleed resistor allows
| current to flow from one side to the other, balancing the
| charges on both sides so there is no relative voltage. Q=CV
| Waterluvian wrote:
| Thank you! I understand this now.
| mytdi wrote:
| Great explanation, very helpful! Thank you!
| nathan_f77 wrote:
| I'm working on a project where I may need to open and repair
| an old device that probably contains some high-voltage
| capacitors. Would it be relatively safe to do this if I was
| wearing rubber gloves + shoes, and used a multimeter to check
| for voltages, and a large resistor to discharge any
| capacitors? What kind of bleed resistor is typically used,
| e.g. for old TVs?
| eurasiantiger wrote:
| Just short the positive side to ground to discharge them.
|
| Note: do NOT do this with thin wires and large capacitors /
| arrays of capacitors, or you may get a hot copper shower.
| jstanley wrote:
| Preferably connect it to ground through a resistor.
| barbegal wrote:
| If it's 250V or less then that's probably overkill. Rubber
| gloves alone will protect against a few hundred volts.
| Bleed resistors depend on the capacitor size but are
| usually in the high kilaohms.
| _fizz_buzz_ wrote:
| > a multimeter to check for voltages, and a large resistor
| to discharge any capacitors
|
| That's all that I use. Don't hold the resistor in your hand
| though, depending on the size of the capacitor they can get
| quite hot. I usually use some pliers to hold the resistor.
| amelius wrote:
| This might be a nice feature of a multimeter: discharge
| mode.
|
| Putting the leads over a capacitor, the multimeter will
| show the voltage and discharges the capacitor with a
| constant safe current. Beeps can be used to indicate when
| the capacitor is safe to handle or not.
| prewett wrote:
| It kind of already has a discharge mode, just short the
| leads of the capacitor with one of the probes.
| yrro wrote:
| How does this work in practice... do compliant capacitors
| have to be designed to 'leak' stored charge across an
| internal resistor or something like that?
|
| [edit] Ah I see this is called a bleed resistor, never mind
| _fizz_buzz_ wrote:
| They usually just have a normal resistor in parallel with
| the capacitor. In my experience it's also kind of nice to
| have minimal load at the output, which makes it a bit
| easier for the voltage controller.
|
| https://en.wikipedia.org/wiki/Bleeder_resistor
| belter wrote:
| Computer was unplugged:
|
| "Shawnee teenager is electrocuted while working on a
| computer":
|
| https://www.kctv5.com/story/19767067/teen-electrocuted-
| while...
|
| Same story as above as link not available:
|
| https://www.dailymail.co.uk/news/article-2215200/Teenager-
| Sh...
|
| And a warning:
|
| "I just received an electric shock from an unplugged
| computer"
|
| https://www.reddit.com/r/computers/comments/53cio2/i_just_re.
| ..
| hulitu wrote:
| IEC states what should happen. I strongly suggest making sure
| that the capacitors are discharged before working on any
| circuit.
| janci wrote:
| Probably this is only about exposed terminals? Like touching
| the power plug will not shock you, but poking at the
| internals could.
| bpoyner wrote:
| I had a friend in high school who found it funny to hand
| unsuspecting people a fully charged capacitor he pulled from
| a camera flash. This was 30 years ago, before "modern
| electronics", so the charge lasted longer than a few seconds.
| Why this never started a fight I don't know.
| LeonM wrote:
| > before "modern electronics", so the charge lasted longer
| than a few seconds.
|
| If you take any capacitor and charge it, it'll take quite
| some time to discharge on its own.
|
| The discharge is usually controlled by a resistor in
| parallel with the capacitor on the PCB. Removing the
| capacitor from the board disconnects it from the discharge
| resistor. So not much "modern electronics" going on here
| :-P
| [deleted]
| kleiba wrote:
| How do you find a broken capacitor on a board?
|
| The article says it was clear that the cap was "swollen" but how
| do I know what a swollen cap looks like?
|
| And what if it's broken but not swollen?
| 101_101 wrote:
| you look for a short and try to isolate the section. there are
| lot of videos on youtube. try eevblog and old rossmann videos.
| electronic repair school is also good.
|
| edit: you will be able to tell a swollen cap, but if you are
| not sure you should definitely learn the basics first. large
| caps can store a charge and can hurt you.
| ta988 wrote:
| look at the other capacitors. the top is really flat. you can
| even spot those that start to fail because light will reflect
| slightly differently on top of them.
| Fradow wrote:
| It's very noticeable when you pay attention and compare it to
| the others. There are generally a lot of capacitors there, and
| only one or two will be swollen (the top part is supposed to be
| flat or even slightly curved inward, if it's curved upward,
| it's bad). Really, if it even looks slightly out of place,
| change it, capacitors are dirt cheap.
|
| I'm not sure it can be broken without being swollen, or at
| least that's not a frequent failure mode.
|
| Having repaired a few displays just like that, I can say it's
| really easy provided you are able to open the display and
| solder on a basic level, which anyone can learn in an
| afternoon.
|
| On the other hand, not all display will be that easily
| repaired. Sometimes, you cannot easily identify any swollen
| capacitors, or there is a burn mark somewhere else, or
| something else that you cannot identify (and thus order a
| replacement for). In those cases, unfortunately it generally
| doesn't make sense to bring it to a shop to be repaired by
| pros.
| meemo wrote:
| I just had a newish (but out-of-warranty) LG 4k monitor go bad on
| me. The picture went mostly dark, with a few streaks of white. I
| figured how to take off the back panel, but then got them stuck
| removing the EM shield covering the main board. I got all of the
| screws off, but then it wouldn't come off.
| CivBase wrote:
| Consider sharing this on repair.wiki.
| knolan wrote:
| I've don't similar fixes over the years soldering replacements
| for dead components and changing the CCCL in a laptop.
|
| I was surprised by how simple and spacious the boards in these
| displays are, easy for an oaf like me to replace components on.
| Just find where the magic smoke came from and order a replacement
| part for pennies.
| bayindirh wrote:
| A had an awesome (for its time), Hyundai L90D+ monitor, and used
| it for ~8 years.
|
| One day it turned and stayed off, sent it to some local shop for
| repair, and the tech told me that he added another light control
| circuit and, my brightness had to be adjusted via an external
| control. He also said that two ICs damaged, and he cannot source
| any.
|
| I got pissed, found the parts, removed the other abomination and
| changed the damaged parts myself.
|
| The monitor came back alive for 30 seconds and then died again.
|
| It had no leaky caps, no visible damage, nothing on the board.
|
| Had to trash it.
|
| So, YMMV.
| Laforet wrote:
| The board had probably developed a short somewhere because one
| of those tiny ceramic SMD capacitors had failed which is very
| hard to tell just by looking at it. Or the PCB substrate may
| have degraded, allowing two traces to come into contact but
| this is less likely.
|
| The tech probably figured out that this was happening but was
| unable or unwilling to isolate the issue.
| bayindirh wrote:
| > The tech probably figured out that this was happening but
| was unable or unwilling to isolate the issue.
|
| I suspect. It was just a run of the mill repair shop. If he
| had found it, it would have warned me when I told him about
| my future intentions.
| rock_artist wrote:
| Since the days of ISA and DIMMs I've been 'fixing' things myself.
| I also do all sort of 'handy-man' work at home.
|
| Being 'technical' I'd still suggest evaluating things before
| engaging to them.
|
| Some repairs aren't worth it. this is per-basis calculation based
| on your capabilities, experience and time.
|
| So the important word is... MAY be easier... maybe it won't be
| easier than you think ;)
| squarefoot wrote:
| I've repaired several TVs and monitors, LED lamps, etc. just by
| replacing bad capacitors, and in a few cases some diodes too, so
| it's worth trying especially on electronics that would otherwise
| be thrown away. If you see a TV/monitor going off randomly or a
| LED lamp starts flashing, pretty sure there are one or more
| defective capacitors in there.
|
| Defective capacitors are a common plague in modern electronics,
| and the culprit is always the capacitor: the market is literally
| invaded by rubbish quality capacitors, and swapping a bad quality
| one with another bad quality one guarantees it will fail again
| one day, so buy only reputable parts from reputable vendors;
| avoid online purchases of branded parts from unknown resellers
| (pretty sure that 99.999% of Nichicon or ELNA capacitors sold by
| any Aliexpress, Ebay, Amazon, etc. sellers are relabeled fakes);
| pay them more but pay them once. A web/image search for
| "counterfeit capacitors" works better than 1000 words.
|
| Anyway, when shopping for (hopefully genuine) electrolytic
| capacitors, respect also the temperature ratings. Capacitors
| mounted into a power supply are exposed to higher temperatures,
| so always choose the 105c degrees type. Capacitance is usually
| not critical; electrolytic capacitors accuracy can be worse than
| 20%, and that's not a problem because they're not required to be
| accurate for their job, so if you don't find the exact value, you
| can safely swap the part with one with slightly higher
| capacitance; same for the rated operating voltage which can be
| higher (not lower!). Low ESR rated ones are preferred; if you
| can, buy them instead of generic ones.
| riedel wrote:
| Planned obsolescence using wrongly placed capacitors is one of
| the few conspiracy theories I tend to believe in (I guess it is
| conspiracy). I also successfully repaired an old telefone
| system, a washing machine and an old TV 15 years ago because
| the same capacitors failed so frequently that even without any
| knowledge one would be able to Google what needed to be
| exchanged together with order links. However, I think
| manufacturers really found better strategies for planned
| obsolescence eg. by introducing new communication standards or
| turning off server and not providing software updates. So
| during the last 10 years I mostly threw away fully functional
| hardware...
| eurasiantiger wrote:
| Low ESR only matters for PWM filtering capacitors, such as
| those found in monitor backlight drivers and some switching
| power supplies' secondary circuits.
|
| It is not necessary to use such capacitors on the primary side,
| i.e. when the large capacitor nearest to the mains input dies,
| just replace it with a normal electrolytic capacitor that
| matches or exceeds the original's voltage rating and closely
| matches its capacity.
| klodolph wrote:
| Worse yet, sometimes the circuit won't work with a low-ESR
| capacitor. For example, you can't put a low-ESR capacitor on
| the output of an LM1117, it will oscillate.
| eurasiantiger wrote:
| In a pinch, that could be compensated with a resistor, a
| few ohms would suffice... :)
| grishka wrote:
| Huh. I have a Dell monitor that suddenly started showing these
| kind of smeared stripes instead of a proper picture. Took it
| apart, looked carefully at all the capacitors and other
| components on both boards, but none looked bad. Disconnecting
| and reconnecting the ribbon that goes to the LCD panel made no
| difference whatsoever. What could it possibly be?
| BatFastard wrote:
| Interestingly I have 5 Dell monitors, and 10 Samsungs that
| are 15 years old. Dells are all still running strong. While
| the Samsungs have needed replacement Caps, and their DVI
| ports have flaked out. I did find that if I use the VGA port
| they will work well though, strange...
| BBC-vs-neolibs wrote:
| Capacitors can be bad but look perfectly fine.
|
| If there aren't many, one can just replace all of them.
| kasabali wrote:
| If there are vertical lines most likely Cof or T-Con board
| failure. Unfortunately it isn't an easy repair. (Although
| some YouTube videos show you can work around some minor cof
| failures by isolating broken lines with a tape)
| grishka wrote:
| Yeah iirc (too lazy to get it out of the closet to test) it
| was vertical lines that somewhat fade in throughout the
| screen, with colors resembling what it's supposed to be
| displaying.
| fouc wrote:
| does a bad capacitor always show damage visibly?
| MisterTea wrote:
| Most likely it will simply NOT power on. That or briefly
| power on and shut off once the ripple spikes and glitches
| everything.
|
| In another post here I mentioned fixing Optiquest monitors.
| The usual issue was you would press the power button and
| the power LED would flah for a second and... nothing. This
| is because the output cap of the switching supply would
| cease to filter the high speed square wave that goes
| through the transformer. So your DC power supply is now an
| AC square wave supply. Of course logic circuits don't like
| that so they will outright fail.
|
| Sometimes there is enough capacitance via decoupling caps,
| ground planes on the PCB and local filter caps on the logic
| board so the initial power up works but once the load
| increases the ripple increases until it becomes AC again
| and everything goes haywire or shuts down.
| ska wrote:
| no. but often does.
| hellbannedguy wrote:
| no
| yitchelle wrote:
| > the market is literally invaded by rubbish quality
| capacitors, and swapping a bad quality one with another bad
| quality one guarantees it will fail again one day
|
| Actually, even a quality capacitor will fail eventually, just
| not as early as the fake ones. As you have mentioned about the
| heat, the capacitor will be exposed to it and will fail because
| of it.
| Laforet wrote:
| I have replaced more capacitors in appliances than
| electronics. The fact that appliances runs on higher voltages
| and stop/starts frequently exacerbate the heat problem.
|
| The 9 years old range hood in my kitchen is already had the
| start capacitor replaced twice. Whoever designed this unit
| decided to place the circuitry right in a hot spot, making
| sure that the capacitor will be gently toasted to death in a
| couple of years.
| naikrovek wrote:
| good caps go bad, too. service lifetime is a function of
| temperature and time. lower the operating temp by 10degC and
| you double the lifespan of the good name-brand capacitor, and
| probably quadruple the life of the crappy generic cap.
| BizarroLand wrote:
| Then again, if the item you are repairing is 4 years old or
| more, then the original caps have enough life span to justify
| using same quality replacements. Sure, you might only be
| saving 30 cents on an individual item (not counting
| shipping), but if its what you have on hand there's not
| really a downside.
| MisterTea wrote:
| Aye I remember bringing back a lot of dead monitors, TV's and
| even a cheap Pentium 4 motherboard by swapping caps.
|
| A place I worked at had a bunch of 19" Optiquest LCD monitors
| which ALL eventually died from a single bad cap on the power
| supply board. I fixed every one of those monitors, think it
| cost less than $10 to order the caps from digikey.
| dehrmann wrote:
| How do you figure out which ones are bad?
| squarefoot wrote:
| Some can be easily spotted by visual inspection for being
| bulged just like the one in the linked article photo,
| others will need to be measured.
|
| Leakage (ie, when a capacitor exhibits resistive properties
| by conducting current also when fully charged) can be
| measured easily by using an analog tester or a digital one
| plus a few parts, while the ESR (equivalent series
| resistance) measurement would need a proper instrument
| called ESR meter. The ESR is an unwanted static series
| resistance the capacitor would exhibit no matter the
| frequency it works at, it increases with aging and it's
| independent from the capacitive reactance which it's
| related to the frequency. Therefore, the lower the ESR, the
| better quality or condition is the capacitor.
|
| However, you can just ignore the 2nd sentence if repairing
| a device would require just a bunch of capacitors; quality
| ones aren't that pricey, and if you find a bulged one, it
| is often advised to replace all capacitors employed in the
| same stage anyway. Some in fact can degrade without showing
| any visible hints of their condition.
| [deleted]
| derac wrote:
| https://www.ifixit.com/Wiki/Troubleshhoting_logic_board_com
| p...
| gruez wrote:
| Why is "VGA" mentioned? Does the fix only apply to monitors with
| a VGA interface? This looks applicable to any monitor with a
| internal power supply.
| ta988 wrote:
| You can do that to any monitor, even recent ones.
| mdip wrote:
| I think more than a few of us are familiar with the mess of bad
| capacitors that made their way into products throughout the early
| 00s. I still see this from time to time, but I remember the first
| time I encountered it -- I had purchased a $200 SageTV Media
| Streamer (v1) and it failed a few months out of warranty. I
| replaced it with a v2 and put the v1 in the basement.
|
| Then Google bought SageTV[0] and they stopped producing
| software/products. Meanwhile, I wanted another TV hooked up.
| Taking apart the device revealed capacitors that -- even though I
| had been unfamiliar with the issues -- were _obviously_ bad --
| one had leaked all over itself, others were bulging.
|
| I hit up ebay, repaired that, and thought about the growing pile
| of unreliable/broken hardware in a room that I had been putting
| off salvaging. That weekend, I repaired about ten LCD monitors --
| caps in the PSU all around, one old plasma TV, 5 ATX power
| supplies and two NetGear 1Gbps switches. _EVERY_ single one had
| varying degrees of damage. All but one power supply was
| functional again.
|
| [0] The product was a TiVo for PCs and was among the best. Google
| purchased them as an acqui-hire and -- I think -- used portions
| of the software in their STBs for Fiber. They later released the
| code open source.
| spookthesunset wrote:
| > Then Google bought SageTV[0] and they stopped producing
| software/products.
|
| Man I remember when that happened. I was happy for the SageTV
| devs but I knew that was the end of a great run. SageTV was our
| DVR for years... It was such a cool product!
| glugc wrote:
| Opening Amazon and buying a new one is even easier and you end up
| with a more modern and therefore better product.
| G3rn0ti wrote:
| Well, people complain about Bitcoin to kill our climate but on
| the other hand have no problems to buy new monitors when it's
| not necessary ...
| mrweasel wrote:
| I don't completely disagree. VGA should have been removed from
| monitors 10 years ago. Some companies still buy new monitors
| and hook them up via VGA. That should be prohibited by labour
| laws. The image quality wasn't good enough to be used for an
| entire work day in 2010 and it certainly isn't acceptable
| today.
|
| Tens years ago I argued with a previous boss that it didn't
| matter how cheap the monitor was, he shouldn't force anyone to
| use a VGA monitor and hurt their eyes when DVI was available
| and only slight more expensive.
|
| That being said, if you need a VGA monitor, perhaps for some
| retro computing or a system that only supports VGA for some
| reason, it's better and cheaper to just fix it, if possible.
| silon42 wrote:
| Just like 3.5mm headphone jack. No.
| cesarb wrote:
| > or a system that only supports VGA for some reason
|
| AFAIK, nearly all modern servers only have VGA, serial,
| network, and a couple of USB ports, so it's much more common
| than you think. Of course, most of the time you'll be
| configuring them through the dedicated management network
| interface, so the VGA and serial outputs are mostly a
| fallback.
| jonathanlydall wrote:
| I think these days that you don't really pay extra to have an
| HDMI port on a monitor. As HDMI is signal compatible with
| DVI, you can just use a passive adapter if your computer only
| has a DVI output.
|
| I have considered digital inputs (DVI, HDMI or DP) mandatory
| for any monitor I have purchased for myself since 2010 and
| when people ask me for advice on monitors I advise the same.
| HPsquared wrote:
| I think with VGA, being analog, the image quality depends on
| the specific hardware. I've used monitors on 1080p 60Hz using
| VGA cable and it's been fine. On the other hand, I've also
| had poor image quality (ghosting) at the same resolution with
| a different cable and monitor. So it is possible to have
| decent quality on VGA, but not guaranteed.
| blueflow wrote:
| "modern" does not imply "better" anymore, for at least a decade
| now.
|
| Think of SmartTV, microwaves, or every kind of consumer
| electronics in general.
| kichimi wrote:
| I do think you should open your mind a bit. Smart TVs are
| pretty terrific, I can just cast whatever I want across the
| room and bam, it's on the TV. Friends can come over and share
| the input. I can lay in bed with nothing but a remote and
| browse my plex library.
|
| I used to go along this line of thinking, and had a "dumb" TV
| for a long time. I would spend hundreds of hours trying to
| get a PC/xbmc/kodi setup with a remote control to be
| comfortable, but always required a keyboard and mouse next to
| the TV. In the end it was a waste of time and I wasn't
| enjoying my TV as an entertainment device.
|
| When I finish work, I want to sit down and just have
| everything work. I don't want to have to keep getting up and
| pressing buttons and messing around to get a myriad of
| supplemental devices of varying quality to work. I just want
| one single device, on the wall, with a remote.
| blueflow wrote:
| What you didn't include: the data gathering and the ads.
| tons of ads. I interacted with smart TVs before, but when i
| pay for it and it displays me ads in the UI, its an instant
| return. I'll have none of that shit.
|
| And don't get me started on weird bugs that i can't even
| fix myself. Stuff like my dad's TV randomly outputting 1-2
| seconds of audio of the last selected sender /while being
| turned off/. Audio only, with the screen turned off. Just a
| few moments. Nightmare fuel when its dark and you are
| sleeping in the same room.
| kichimi wrote:
| I don't experience ads with my TV. I don't understand why
| this is an often repeated point. I've had three so far
| (due to moving countries), and never experienced this
| "tons and tons of ads" thing I see people complain about.
| It's always just been a UI and some apps.
|
| Regarding data collection, who cares? Just get a pi hole
| if you really care about that.
|
| Also you are describing a fault that can occur with a
| dumb tv.
|
| EDIT: okay. I found this https://external-
| preview.redd.it/DcKcaASCdFkfM-eK5pOiu6DIOZb...
|
| I have a samsung TV and I do not see this. Perhaps this
| is a region thing. I've lived in The Netherlands and the
| UK and not experienced this.
| josefresco wrote:
| Dumb TV + Streaming stick is the way to go. Bundling your
| TV (hardware) with your smart TV (software) is a recipe for
| disappointment and frustration 2-3 years down the road when
| the tech evolved and your TV manufacturer has lost interest
| in supporting your model (looking at you LG)
| jonatron wrote:
| Power supply caps fail so often that maybe they should be
| socketed?
| ksec wrote:
| The answer isn't socketed but high quality capacitor ( Solid or
| Tantalum etc ) . Swollen capacitor should really be a thing of
| the past.
|
| Unfortunately Capacitor is an area that is easiest to cut cost
| and has no immediate effect on the devices function and are
| hard to spot. Part of the reason why I switch over to Mac ~20
| years ago. I dont want to spend time looking at every capacitor
| on a motherboard or to gather enough information on all these
| details. That was before the time when Capacitor marketing on
| motherboard was a thing.
| raxxorrax wrote:
| > Capacitor marketing on motherboard was a thing.
|
| That is a thing? What do they advocate, the fine smell of
| rotten eggs when they die?
| BizarroLand wrote:
| Last mobo I bought proudly talked about their "Military
| Grade Capacitors" which is funny because if you know
| anything about Military Grade that means "whoever will
| provide a product that meets minimum spec for the least
| amount of money"
| [deleted]
| ksec wrote:
| It was a long long time ago, before Solid Capacitor were
| affordable enough to be used in mainstream electronics. Now
| they are expected in any quality motherboard. At the time
| they used to market brands like RubyCon for exceptional
| stability or another brand which I cant remember for
| similar marketing reason. And redundant capacitor etc.
| 101_101 wrote:
| so, you are not a business guy huh? lol plus it's more work &
| cost more to include sockets.
| bserge wrote:
| Why would they be? Less money for the manufacturer.
|
| Just throw the whole thing away (preferably in the garden waste
| bin for that extra good feeling) and buy a new one. /s
| kalium-xyz wrote:
| Nah soldering isnt that hard an operation and sockets are
| expensive.
| contravariant wrote:
| Though it'd be nice if they made those kinds of things more
| easily accessible, rather than hiding it behind tons of
| warranty stickers and really tiny screws.
| kalium-xyz wrote:
| Sure, just saying that it not being socketed should not be
| that big a barrier to entry. If you want an awesome way of
| doing things look at old tektronix scopes
| https://w140.com/tekwiki/wiki/Ceramic_Strips
| BizarroLand wrote:
| I'm assuming that the reason why there's so much
| discussion about soldering techniques and practice on
| that page is that the tubes failed on a predicable
| schedule and user servicing the machine was a mandatory
| part of ownership, right?
| kalium-xyz wrote:
| The tubes are socketed. Not sure if the soldering was
| entirely meant for the users or for specialized
| maintainers, might have been a mix. these things cost the
| price of a new car and came with similar
| responsibilities. The soldering techniques are to prevent
| bad contacts or impurities as this is sensitive
| measurement equipment.
| squarefoot wrote:
| Whoever uses junk capacitors to save some cents would never
| ever spend more money to add a socket. That is not the problem,
| shitty parts are.
|
| Good capacitors do exist, but they're getting less common with
| time; actually you're more likely to find good electrolytic
| caps in a 30 years old radio than in a 5 years old one. Today
| some manufacturers are cutting corners everywhere and parts
| quality tanked.
| mikewarot wrote:
| Since the title specified a resolution, I assumed a VGA CRT with
| a DB15 connector. (Not an MDA, CGA or EGA) I was all set to warn
| you kids about the dangers of CRTs, high voltage, Xrays, and of
| course the implosion if you break the neck of the tube... and
| instead got bad capacitors on LCD displays.
|
| Regardless of what the safety standards say, you should always
| remove power, and short any capacitors with a screwdriver or
| freshly checked jumper lead, as bleeder resistors (and jumper
| leads) fail. LCD backlights with cold cathode fluorescents use
| quite a bit of voltage, so be careful, and good luck!
| jve wrote:
| Thanks. I appreciate when someone gives safety advices as they
| come in handy when starting to tinker electronics. When
| repairing dishwasher I had to disconnect a huge capacitor...
| well it looked like it. Knowing what you just wrote about
| capacitors, it gave me shrugs and I was VERY careful handling
| that piece of thing.
|
| Can you give any advice on what good fume extractor for
| soldering does and if hobbyist that does repairs now and then
| should care?
| h2odragon wrote:
| Solder fumes aren't great for your lungs, but its not a
| severe health threat: you're not soldering that much. A fan
| blowing at you to keep smoke and fumes out of your face
| should be sufficient for up to a few hours a day of
| soldering. If others in the house complain about the smell,
| then work on venting outside harder.
| scrumper wrote:
| > short any capacitors with a screwdriver
|
| Not universally a good idea to do that, especially not in a
| power supply. Safe enough in some circumstances but not all.
| Better to buy a discharge probe or make one by soldering a 2200
| ohm 5w resistor between a couple of insulated wires.
|
| EDIT: made it less condescending.
| hermitdev wrote:
| I also immediately had flash-backs to opening up an old CRT 13"
| TV that was going flaky (the sort of flaky where sometimes
| percussive maintenance worked). Being an electrical engineering
| student at the time, I thought I could handle it. I knew about
| the high voltage, I knew about the retained charged of the
| capacitors, etc, etc. What I wasn't prepared for was just how
| poorly shielded this thing was once I got it opened.
|
| I shocked myself almost immediately as I was doing basic
| examination. I hadn't even gotten to probing for shorts or
| broken connections. Thankfully, the shock wasn't bad, more
| startling than anything (I remember it being somewhat like
| brushing up against an electric fence). I was wearing a
| grounding strap on the arm of the hand where I got shocked. Not
| sure how much/if that helped any.
|
| That was enough for me to determine I wasn't qualified to work
| on it. I reattached the case and lived with its flakiness for a
| few years longer until it was replaced with an LCD.
| akerr wrote:
| I did this when I was a teenager - with CRT monitors. Higher
| voltages and I had the fun of refocusing the tube and fixing the
| colour registration while it was on, reaching around the back
| while I looked at my test pattern.
|
| I learnt a lot about computing hardware and software on that
| Pentium box: 166 MMX (overclocked to 200MHz), 16MB RAM (later
| 64MB), running Debian and my resurrected 15" LG CRT. Oh, and a
| 56kbps modem.
| [deleted]
| jonathanlydall wrote:
| I did this kind of a repair job to a couple of Samsung 23" 1080p
| screens back in 2012.
|
| A friend gave them away since their backlights would flicker
| making the monitor unusable for the first 10 or so minutes after
| they were turned on, after which they worked completely fine.
|
| I have little to no knowledge of electronics, but did know how to
| use a soldering iron. As I recall, I watched a YouTube video and
| was confident that if the problem was just the capacitors, then I
| could manage to replace them.
|
| I opened up the monitor, saw two or three capacitors which were
| clearly bulging and I used a soldering iron to get them off the
| board.
|
| I went to an electronics shop expecting that someone there would
| be able to advise on replacements which would work. As I recall
| one or more of replacements they had available on hand had a
| different "number" on it, but they assured me it was a higher
| rating and wouldn't affect use, I don't know much about
| electronics, but this made sense to me so I trusted it.
|
| I managed to re-solder them on and they then worked perfectly.
|
| Fast forward to today, about 9 years later, and my brother is
| still using both the repaired monitors. They have DVI input,
| 1080p resolution and VESA mounts so are actually very decent
| unless things like >60Hz refresh rate, higher resolution or very
| good colour accuracy are important to you.
| 22c wrote:
| >they had available on hand had a different "number" on it, but
| they assured me it was a higher rating and wouldn't affect use
|
| It's probably the amount of farad units the capacitor is rated
| for. You can often use a capacitor with higher farads as long
| as the voltage is the same and it can be even more reliable
| than the original part, the only trouble is sometimes they are
| physically larger or taller, so you have to be careful if
| you're working in tight spaces.
| foldr wrote:
| Seems more likely that it would be the voltage rating? While
| it's true that a larger capacitance would be fine in many
| applications, it wouldn't always be (e.g. if the cap is part
| of an RC filter or if it's used as a bypass cap). In contrast
| the voltage rating of a cap is just a maximum.
| squarefoot wrote:
| Tangentially related: many VGA monitors can be given a new life
| by driving their panel using cheap ready made controllers. Search
| for "hdmi controller board" on Ebay, Aliexpress etc. Some are
| programmed in advance and the seller must be given the exact name
| of the panel they will work with before purchasing, while others
| are sold ready to be programmed. Some can also drive large TV
| screens.
|
| Here are some links that might turn out useful.
|
| http://www.elecrealm.com/down/class/
|
| http://www.mattmillman.com/info/lcd/rovatools/
|
| https://github.com/ghent360/RTD-2660-Programmer/
|
| https://sites.google.com/site/lcd4hobby/home
|
| http://openrtd2662.ru/
|
| https://www.codeforge.com/article/258602
|
| https://www.panelook.com/index.php
|
| http://lcdtech.info/en/
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(page generated 2021-09-09 23:02 UTC)