PowerBook 520c white screen of death

[mitchW]

I just bought myself a nice condition PB 520c which was said to be working.

When I powered it on, it only showed white picture, so I guessed that the contrast must be off or something. I perhaps saw a very very faint picture in the background of the Mac OS loading screen. The contrast control doesn't react when pressed.

As I recently also got a PB 165 with similar problem (it needed new caps on the LCD panel), I was wondering if the 520c was also affected by this.

What should I try before opening it?

 

[mitchW]

I solved the problem. The picture came at different screen angles, so I figured that it must be the connection issue.

I took the whole PB apart, cleaned all the connections with the contact cleaner and then put it all back together.

I also checked the LCD screen, and it has some electrolytics at the back, but all of them are small radials (through hole) Nichicons 50V unknown value.

Also there is a SMD 100uF 25V cap on the logic board that may leak in the future, but for now I left it there. There are also two SMD caps on the modem board (4,7uF 16V and 10uF 16V), which may require replacement.

 

[Elfen]

Glad you solved it.

 

[TheWhiteFalcon]

I need to do this to mine, it looks like, though mine goes dark, not white. Only happens when I move the screen a certain way though.

 

[reukiodo]

My 520c just recently started to have this issue and I found

for the fix which seems to mention a 22uF, 6.8uF, and 220uF capacitors on the inverter/backlight board, but doesn't mention the voltage or placement of each one.

 

[jmacz]

Post in thread 'PowerBook 540c Restoration Project'
https://68kmla.org/bb/index.php?threads/powerbook-540c-restoration-project.44990/post-494827