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Powerbook 180c screen problem after recap, can someone help me?

Hi everybody,
the problem:
I replaced the capacitors in the screen of my 180c, at first everything was fine, the screen had recovered its colours and no longer showed the typical horizontal artefacts. unfortunately after a couple of hours of work one of the four horizontal bands started to give problems: the colours disappeared and the image became corrupted, then the situation returned to normal for a few minutes and then started to return a corrupted image again. Now the band is permanently switched off. See attached pictures and video.
Do you have any ideas? Could the problem be related to the replacement of the capacitors? I don't know but maybe a capacitor is assigned to one of the four horizontal bands of the screen?
If anyone can help me, I would be very grateful.
best regards

MattiaIMG_5456.JPGIMG_5453.jpgIMG_5452.JPG

View attachment IMG_5460.MOV
 
I mean: maybe the four capacitors I highlight in the picture are connected to the 4 flex cables that handle the corresponding 4 image bands horizontally?
I am not an expert so this is just a guess. But the fact that before the recap the screen was working fine makes me suspect that the problem is in the capacitors.
Any help is invaluable.
thanks again
180c caps (board).jpeg copia.jpg
 

3lectr1cPPC

Well-known member
check the display ribbons that go between the board and the panel, you'll have to remove the metal shield to do this (bend the metal clips). They may have been corroded by the caps in which case you're screwed. My guess would just be that one cap goo is left on the board, you've got to take the metal cage off and clean both sides of the board really well to get it all off.
 
I have already detached the panel and cleaned both sides of the board with IPA and a brush.
The only thing I noticed was some corrosion in the ribbon welds, but I don't think that could be the cause of the problem.
Looking at it, the board doesn't look too bad

IMG_5522.jpg
 
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3lectr1cPPC

Well-known member
Looks fine to me. Could be that the IC itself has failed, but it still seems like a bad connection somewhere. Check the ribbon cable to the base?

@techknight is our resident technical laptop wizard here, so I'm going to @ him here to see what he thinks is up.
 

desertrout

Well-known member
I've seen situations where an over-enthusiastic use of IPA can dissolve the glue in a driver and affect electrical connections within (ask me how I know)... what happens when you add some pressure to the driver (or near it) while the panel is powered?
 

ian1035nr

Well-known member
I'm over a month late, but I had a similar problem after recapping my own 180c display. My guess as to what happened is the temperature from the soldering iron ended up affecting the cables running from the PCB to the LCD.

There's another thread on this forum of people dealing with a display defect on older PowerBooks. The nature of their problem and the issues it causes are totally different from what's happening here, but there's one nugget on information in there that's useful: People have baked their screen in an oven at 220 degrees Fahrenheit for 45 minutes without causing any damage to the PCB or polarizer.

I baked my PowerBook 180c's display, and that restored the connections. It now operates perfectly. If you want to try this route, make sure the screen is facing upwards and cover the LCD itself with some aluminium foil, leaving the cables visible.
 

tedcy

Member
Did you ever get this resolved? I have the same problem after recapping the 180c screen (3rd band from the top is almost dead).
 

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