[HN Gopher] Hardware fix for Dell "AC power adapter could not be...
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Hardware fix for Dell "AC power adapter could not be determined"
Author : onny
Score : 68 points
Date : 2020-05-25 19:42 UTC (3 hours ago)
(HTM) web link (blog.project-insanity.org)
(TXT) w3m dump (blog.project-insanity.org)
| yftsui wrote:
| Dell Laptop PSUs has this for at least 15 years. Internally it
| use a DS2501 to store the manufacturer, wattage, output voltage,
| output current, Dell SN and check sum. It is more like EDID for
| power supplies, it is definitely not DRM. It helps the laptop to
| understand how much wattage it can get from the PSU to avoid over
| heating, and use the output voltage to determine whether it is
| safe to use it to charge the battery.
|
| The content is something like `DELL 01 AC 065 195 033 {23bytes}
| 01`, where 01 matches the revision number on the label of the
| PSU, 065 means it is a 65 watts adapter, 195 means the output
| voltage is 19.5V, 033 means the output current is maxed at 3.3A.
| The {23bytes} contains the country where it is produced, the Dell
| part number and date codes which I don't have enough data to
| understand how that is coded.
|
| There was a github project which provided tools to copy and
| reprogram the chip, HP follows a similar protocol for its high
| end laptops, it is possible for a Dell laptop to use a HP PSU, if
| the BIOS is not implemented correctly.
| Causality1 wrote:
| Not _only_ DRM.
| yftsui wrote:
| Doesn't DRM means they tried hard to stop you from clone it?
| Any hobbyist can get a sample chip from Maxim, clone the data
| from the original PSU and write it to the new chip.
|
| I agree it should be an open standard, but the implementation
| is really similar to EDID. As we are moving forward with
| USB-C power supplies, this is probably going to be irrelevant
| very soon.
| Causality1 wrote:
| Yes, I'm sure it has nothing at all to do with forcing
| customers to buy OEM chargers for $119 a piece plus tax and
| shipping instead of buying a generic one for $30.
| tjoff wrote:
| Which I guess is among the things usb-c power delivery covers
| as well.
|
| Usn-c for charging, despite its warts, are quite the game-
| changer. Especially in these absurd times where batteries are
| non-replacable being able yo juice-up from a power bank is
| fantastic. (yes you could do that before but it was very niche
| and/or expensive and with less utility).
| andrewshadura wrote:
| I guess it's possible to build something similar to this, but
| for Dell: https://www.tindie.com/products/mikepdiy/lenovo-
| charging-por...
| majormajor wrote:
| Something I discovered the other day, while looking for a
| high-wattage Dell USB C adapter to use with my older XPS 15
| (which came with just a old-school charger, so it doesn't get
| full juice out of most other USB C ones) is that the new 130W
| Dell USB-C charger only shows up as 90W on an older one like
| mine.
|
| Looking around, stuff like this isn't uncommon. Apparently a
| lot of HP's won't work with non-HP USB C chargers at all, for
| instance.
| compumike wrote:
| Side note: integrated batteries are still replaceable if
| you're handy. (Though not quickly swappable like you're
| suggesting for more energy capacity over a single day!)
|
| On the MacBook Pro I'm typing on right now, I replaced my the
| battery myself a few months ago. It took about an hour
| including a thorough cleaning of the laptop internals and I
| documented it here
| https://www.youtube.com/watch?v=CAYFDDxUxHA . That's still
| 59.9 minutes longer than it would have taken if had a modular
| battery, but about the same price in dollars. And a fun
| little weekend project.
| frosted-flakes wrote:
| Or do something like charge one phone from another.
| effnorwood wrote:
| Have you heard of eBay?
| battery_cowboy wrote:
| My dell died recently and I wasn't sure why, since all the
| components that I could check were working. It seemed like the
| thing just had no power. I sent it for recycling after stripping
| some parts, but now I wonder if this was the issue I had. I
| didn't get a Dell for my replacement, so I'm happier now with a
| lighter, nicer computer anyways.
| klmadfejno wrote:
| I was bit by this issue once. I was still using the original
| charger. The issue wasn't anything wrong with the pin, but the
| power port had been slightly pushed inward. Had to crack it open
| and solder it to the frame.
|
| I don't buy dell laptops for this exact hardware flaw.
| kls wrote:
| I can second that, it really turned me off to Dell's I switched
| from a high end Dell to a Sager for this exact issue.
| mrleinad wrote:
| Similar issue about 2 months ago. When plugging the power in,
| it seems I introduced the cable at an angle and the pins inside
| the port caused a short. Fortunately, nothing was irreparably
| damaged. Had to dissasemble the port, unbend the pins into
| their correct position, and plugged them in again. Didn't
| realize that was the problem until I had dissasembled the port
| and thoroughly checked it, so those were quite a few minutes of
| panic!
| TaylorAlexander wrote:
| Proprietary technology slows us down and increases waste.
| 1996 wrote:
| Do we really need DRM for AC power adaptors?
| MintelIE wrote:
| Of course not. This is just yet another excuse for a vendor to
| lock you in.
| zootboy wrote:
| I'd argue it's not really DRM, it's more like device
| identification. Nearly all modern laptop power supplies do this
| in some way. HP and Lenovo ones use a resistor on the extra
| pin, while Dell has put a 1-wire memory chip.
|
| The main reason for this is so that different wattage power
| supplies can be used with the same connector. The laptop
| determines the power supply type to see if it can safely draw
| its full load.
|
| USB-C takes this one step further by having a full negotiation
| process before supplying any of a number of voltage / wattage
| levels.
| londons_explore wrote:
| The kinda-standard way to solve this problem is:
|
| The power supply is "constant current, constant voltage" -
| ie. it is 19 volts for all currents under 3 amps, but if you
| try to exceed 3 amps, it will supply exactly 3 amps at
| whatever voltage that works out to.
|
| The benefit of this scheme is it's super easy to implement on
| both sides, and fully universal - the device just keeps
| increasing the current draw till the voltage starts to drop,
| and it then knows it's hit the limit. The device doesn't need
| any kind of logic at all - a dumb light bulb will either work
| if there is enough power, or not work if there isn't, but
| nothing will get damaged.
|
| It's also compatible with Y splitters - so you can plug in
| two laptops to the supply, with no extra electronics, and
| both can share the power. (there is no guarantee of _even_
| power splitting tho!)
|
| A big benefit is the power supply can have fully variable
| capabilities - for example, most power supplies are thermal
| limited, and on a cold day it could offer slightly more
| current to charge your battery slightly faster - all without
| any digital logic, protocols, or anything manufacturer
| specific.
|
| Anything more complex with sense resistors, ID chips, extra
| wires, etc. just costs more, and provides less utility, and
| almost looks like a deliberate attempt to reduce
| compatibility and increase sales of chargers.
| frabert wrote:
| Unfortunately this only works if the load device is
| compatible with the full voltage supplied. This is not the
| case for USB devices, for instance.
| yjftsjthsd-h wrote:
| > I'd argue it's not really DRM, it's more like device
| identification.
|
| I suppose the key question is: Does it identify the device
| and then decide not to work with non-Dell devices? It's fine
| to read required information, but _unnecessarily_
| constraining what happens based on that information brings it
| back to DRM.
| arcticbull wrote:
| It's not an open standard so this isn't really meaningful.
| The data has to be formatted a specific way, the Dell way
| that is, but it's not signed or anything.
| cesarb wrote:
| I'm not sure the intent of that identification chip is DRM.
| There are several kinds of power adapter (at least 65W and 90W,
| though I've been told in another comment at
| https://news.ycombinator.com/item?id=23292819 that there's also
| 130W, 180W and 230W), all using the same plug; that
| identification chip allows the embedded controller to know how
| much power it is guaranteed to get from the power supply, and
| if it's enough to charge the battery.
| amluto wrote:
| It's more than working vs not working. The power management
| on the laptop will presumably adjust its charging speed to
| avoid overloading the power supply.
| amelius wrote:
| No, and it will probably not hold up in Europe.
| dogma1138 wrote:
| It did held up at least to some extent laptops that have
| bigger desktop setup high power and smaller lower power
| travel adapters needed additional data to identify the type
| of charger, some would default to lower power settings for
| adapters that aren't original OEM parts, some won't work.
|
| With USB type-c chargers it became more or less redundant
| although the USB type-c power spec implementation is all over
| the place with many cables and chargers on the market capable
| of ruining your devices completely.
|
| This isn't as much of a DRM as a reliability measure if you
| are going to use cheap power adapters you are quite likely to
| be able to ruin your laptop.
|
| There are plenty of 3rd party adapters that can send the
| correct signal to a Dell laptop, those who can't usually will
| power the system but not charge the battery simultaneously.
|
| With USB type-C many adapters would charge the laptop at 60W
| instead of the 100-130W that original Dell adapters can, some
| of the certified USB type-c docking stations/adapters would
| be able to charge it at full rate if they are actually
| capable of delivering the current required.
|
| Not everything is done because vendors want to lock you in,
| laptops now are smaller and power hungrier than ever and
| people want to charge their laptops at full rate with cables
| that could barely charge a phone.
|
| With USB-C things will mostly work but will work slower I can
| charge my MBP 15" with my Nintendo Switch power adapter it
| will just take longer and likely will cause the Switch
| adapter to die the few times I had to do it I've noticed the
| adapter cosplaying as a heating plate while charging the Mac.
| nojito wrote:
| Yes because batteries and power adapters can kill you and/or
| cause a fire.
|
| There was an engineer who showed how shoddy many phone chargers
| are and how dangerous they could be.
| foepys wrote:
| I blame Amazon and other reckless online marketplaces for
| this. Why are they not required to check all products they
| lost to conform with local safety standards? Would you buy
| something from a supermarket and take even a 0.01% (or
| whatever) chance that it literally blows up into your face?
| zozbot234 wrote:
| USB-C is supposed to negotiate a voltage and current that are
| safe for both ends of the connection as well as for the cable
| itself. A "shoddy" charger can supply too little power, but
| it's not going to overcharge a battery.
| close04 wrote:
| A shoddy charger can supply mains power to your device.
| Example [0].
|
| [0] http://www.righto.com/2014/05/a-look-inside-ipad-
| chargers-pr...
| ken wrote:
| Interesting hypothesis, but it doesn't explain the pattern.
|
| That's also true of a million other categories of dangerous
| equipment, and yet almost none of them lock out competitors
| by using proprietary interfaces. A shoddy saw blade could
| kill me, too, but I still can go buy any blade from any
| manufacturer and put it in any table saw, and it'll work.
|
| OTOH, there are gratuitous incompatibilities galore as soon
| as you get into software. Network protocols, file formats,
| executable formats, and so on.
|
| What could explain the situations where we see compatibility
| versus incompatibility? If it's obvious and visible, and
| Average Joe can make it fit (like with a hammer), they go
| ahead and make it compatible. If it's secret and internal and
| they can hide the differences in ways that Average Joe can't
| work around (like software), they feel free to make it as
| incompatible as possible.
| bpfrh wrote:
| That isn't drm but certification. E.g. if the device isn't
| certified then you shouldn't use it, but if you still want to
| use it, it is your choice.
| conk wrote:
| This is addressed by product approvals and safety standards.
| Apple, Dell or BestBuy aren't going to be selling knockoff
| chargers. If other stores are selling counterfeit products
| that don't comply with approvals/standards they should face
| fines and criminal charges.
| AnthonyMouse wrote:
| So what does that have to do with DRM? That's what products
| liability suits are for. You sue the maker of the shoddy
| battery/charger. DRM can't protect you from that -- what
| happens when you buy the whole device from the shoddy vendor?
|
| edit: Yes, of course some of the vendors will be gone or
| judgment proof. So don't buy from disreputable vendors. Which
| brings us back to the original problem -- if the user _is_
| willing to buy from them, they could just as easily be buying
| an entire laptop or a toaster for their kitchen. So solve it
| the way you solve those instead of stamping out competition,
| because you need to solve those anyway.
|
| Or put it another way: If _OEMs_ really wanted to solve this,
| they would stop overcharging so much for chargers and battery
| replacements so that people wouldn 't have to play the
| Chinese equipment lottery to avoid paying a 1000% markup.
| NikolaeVarius wrote:
| The product vendor stopped existed a week after you bought
| it from them.
| close04 wrote:
| > You sue
|
| You may not get the chance. Some damage is irreversible and
| a lawsuit will probably only bring you some legal expenses.
| Preventing disasters is smarter and cheaper than inviting
| them and then clogging up a courtroom to complain that the
| perfectly preventable disaster actually happened after you
| invited it.
| ThrowawayR2 wrote:
| Attempting to sue the overseas manufacturer of your no-name
| third party AC adapter is pretty much the definition of
| futility.
| javiramos wrote:
| Does anyone have good recommendations for general office laptops?
| My company bought about 10 Dell laptops and about half of them
| have a problem in which they randomly shut off due to some
| thermal issue. Dell has given us a hard time with the problem and
| have replaced some of the laptops with new laptops that have had
| the same problem.
| bityard wrote:
| Which Dell laptops did you buy?
|
| Dell manufactures the whole spectrum of laptop quality, from
| cheap Walmart garbage to high-end mobile workstations. If you
| buy their consumer-grade stuff, yeah, it's often junk. But
| their business- and professional-oriented laptops are usually
| decent quality. Latitude and Precision, for example. I have
| both of those and they've been workhorses for me.
|
| Mid-range Thinkpads would also be a fairly safe bet.
| rkagerer wrote:
| Now solder that component into an adapter that goes between your
| jack and your third party power supply, and I'd buy it.
|
| I don't even want to use illegit power supplies. Rather, I have a
| growing pile of genuine Dell ones (and jacks) that developed
| intermittent connections on that pin and no longer detect as
| authorized.
| anotheryou wrote:
| usb-c on the XPS just says it's less then ideal wattage (if
| that's the case) and still charges.
| LawnGnome wrote:
| The USB-C laptops just use straight up USB-PD, thankfully, and
| don't have any DRM or other controls. I've charged my USB-C XPS
| 13 off an assortment of Apple, Dell, and generic chargers.
| icelancer wrote:
| Yeah, USB-C is the way to go from now on regarding this
| issue. Using proprietary chargers needs to die.
| lscotte wrote:
| It starts out being Dell then switches to HP? Something funky
| about that article.
| onny wrote:
| ups thanks fixed the typo
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