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Repare Nokia E7 screen and PSP3000 mainboard's super capacitor
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23rd-July-2022
Shanghai, Sunny Hot, 38C
Writing on Lenovo ideaPad 710S ssh & tmux connecting to sdf.org
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## my old devices are recently running no luck
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My old Nokia E7-00 was working well until about a month ago, it's
screen starting to behavior slow and showing some abnormal banner
on bottom of text, icon or any non-backgroud objects, after a bit
of research, it says the screen may deteriorated. But as I was on
holiday outside, only until last week, I was able to buy a
replacement screen module from taobao.com with 28RMB.

My PSP3000 was similar, also about a month ago, it starting to show
some unhappy situation. It doesn't recognize the battery, even the
battery is fully charged, it doesn't boot, and in some lucky case,
it is booted, but will shut down in accidentally when I'm playing
game, or when I put it to sleep mode, it never wake up again. But,
if I plug in the power cable, it will boot. 
I did some research too, people saying this might be the issue of a
Super Capacitor failure. On the mainboard of PSP, there is one
small Super Capacitor Panasonic EECENOF204J1 3.3V 0.2F, this guy is
used to store time and probably also critical for deteching the
battery. I decided to replace myself, So I bought two of them
(5RMB/each) just in case I break one.


## Replacement requires patience and good memory!
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The replacement of Nokia E7 screen is not so difficult, just
disassemble the phone until the screen module following online
instructions. 

The screen is combined with touch screen, so need carefully peel
off the creen, fortunately it has a frame rib out side the screen,
so putting new screen is easy, put it into the frame, that's it.

Putting the phone back is a challenge, It always easy go with the
forward way, but backward usually requires memory and skills. You
would need to use the correct screws, put part in correct sequence,
otherwise may break it self or other later parts. I "successfully"
broke 1 screw and lost 1 or 2 screws, foretunately doesn't matter,
with the limited number of screws still holds the phone together.

The screen shows up colofurlly with no issue, touch screen works as
well, actually this screen is lighting better, the color is sharper
than the old one, I tried play Angry Birds, it works nicely.


## Repair the PSP3000 mainboard needs carefullness, and TIME!
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Repair the PSP3000 is really a tough job! Firstly I need to
disassemble it, until i could take out the mainboard. This is not
so difficult just following online instructions.

However I was stunned by the density of the mainboard and how small
the resistors, capacitors and chips are, and how think the PCB
wires are, and how small the space is between the parts. This is
definetly a obstcle for me to replace parts on it with and normal
soldering iron. But I was really shocked this picece of work that
Sony design and produced about 15 years ago! It's so precise and
elegent design, the cable and connectors are so tiny you could not
even handle by hand! The mechanical design are so well inter-locked
with each other, there needs only a few screw to hold the console!

The Super Capacitor I need to replace is so small and there are
quites some very tiny resistors I really scared I would break them
by mistake. The capacitor is not like a capacitor but more like a
button cell battery in small footprint.

It took me quite a while to take the old capacitor out as it is
revited on two long square nickel plate and soldered on the
mainboard. There is almost no place to put/insert the soldering
iron to melt the tin. At the end, I have to cut the plate, bend one
side away to leave space to melt the tin on the place. This really
took a while to clean the old capacitor away!

Solderiing the new one is another challenge! Knowing the limited
space between itself to other parts, I tried 3 times, and finally
made it, and due to the small space, I failed twice of only able to
solder one plate/pin, but have no space to insert the soldering
iron for melting the tin on next pine/plate. Finally I was able to
solder them all, and the later pin was soldered by its side with
partial connection, anyway that works at the ends!

Then carefully put mainboard back, and connect all the cables, like
cable to function button, to joystick, to play button, to UMD, to
speaker, to power, to ... as the key parts are mostly interlocked,
and positioned by small ribs or plastic pins, so it was not so
difficult to fixing up. I remember only about 10 screws used for
fixing mainboard and front plate. I didn't disassemble the UMD, so
not sure how many more screw there, but I'm really impressed by
Sony's design!

After put all back, I put in the battery, easily powered up, I set
up correct clock, then test whether it will lost time memory by
power off and unplug the battery, wait a few minutes then load the
battery again, the clock is kepted and correct!

I further open up a game, start it, then I push it to sleep mode,
wait a few more minutes, turn back on the power, it worked as well!
I did several more power off and on, every time it powers up
correctly, with no failure at all.

So this proved that it is the Super Capacitor failure cased the
issue of not recoganizing battery and losing RTC clock.

Up to now, all the fixing are done, and sucessful, these two repair
work took me almost a whole day, 1 hours for the Nokia E7 and 2-3
hours for the PSP3000, but this is really rewarding--I could do
some usefull work by myself to fix the old things and allow them
keep serving me.

I like this feeling of achievement and feeling of myself still
capable doing thing by own!

Hope you like the reading, and inspiring you to pick up the
soldering iron!

-Peter