My PowerBook (model 5,6) has a defective display. Only the upper third shows the OpenFirmware or Ambient screen correctly, the rest of the screen is unreadable. For a while I'm using an external monitor which only works at home but is not handy when travelling. I turn the PowerBook on, close the lid, and when the external monitor shows Ambient, I open the lid again for better airflow.
Recently also on the external monitor the display started to show issues. Sometimes it immediately turns black, sometimes it comes back when I press some keys but often not. When the display show up again, it is usually trashed. (Up to here I would suspect the graphics chip.) Sometimes the keyboard also seems to be disconnected: when I hit CapsLock, the LED does not turn on. Sometimes the display comes back after I pressed Ctrl+lAmiga+rAmiga or even the power button instead of resetting the computer. (Here I would also suspect the logic board.)
Here are two pictures of how trashed the screen often looks like in case I can reactivate the display: https://i.postimg.cc/6p6qSwHc/IMG-20220926-154225-small.jpg https://i.postimg.cc/0Np4wRvg/IMG-20220926-154330-small.jpg
In either case I cannot read ther display clearly but after a reset it often works again. Sometimes I have to turn off the computer for a while and then it works again for a while.
The time for the blackout or trashes of the display to happen is very random, sometimes it takes not even a minute after system start, sometimes I can work for two hours.
Can someone make an educated guess what might be the reason for those effects? Overheated graphics chip? Issue on the logic board? Possibly a specific chip or are defective? How to figure out which one and is it worth doing so? If such a guess gets close enough, te question is if it makes sense to repair this PowerBook and how, or whether I should buy another one instead. The DVI cable and connector are fine, it must be anything internal to the PowerBook.
- the PWR button on PowerBooks is mapped to "reset" in MorphOS (you need to hold mit a few seconds to power down) so that is not an issue - pressing keys (in the upper area?) to "fix" the issue would support the idea of a cold solder point or fractured PCB - the KBD also having issue works against the GPU part of that theory
1st order of business should be to open it up, check all connectors (those are only fixed by some tape) loosen the display cable and give it a wiggle while powered on.
Assuming you will be in Neumünster next month I could offer some help: If you suspect the actual display and cable to be still o.k. we could try to marry that to my 5.8 that had it's topcase kinda donated to a "good cause" (I was planning to turn it into a better MacMini). I had some success combining 5.7 and 5.9 parts in the past so that might just work.
You could buy a known good 5.6 or 5.8 but those are kinda rare&expensive these days. You could buy a troubled 5.6 and we will try to combine it with yours to a working one. You could buy a troubled 5.8 with a good display and topcase adding that to mine.
I did get the 5.8 for cheap "as parts" years ago and it turned out to be just some cosmetic issues, an almost dead battery and missing powerbrick nothing that would have been a showstopper for my idea (which I will never come around doing anyways....) or fixing yours so my offer would be 30€ >IF< you end up with a working Powerbook using parts of mine.
I will have to check if it is still complete and works after being boxed years ago so obviously no guarantee......
It is probably enough to apply some flux and heat up the GPU to reflow the balls underneath.
Due to heat up and cool down cycles it is a common problem that prior not perfect connections start failing over time. Usually caused by bumping against the hardware.
If possible try to push onto the gpu while the system is running and see if there are any changes in behavior.
@ Kronos I know how the power button works when the system is intact. In my case the screen turned black, no reaction to mouse movement, key press, caps lock etc., and when pressing the power button sometimes(!) the Ambient screen reappeared. That's not how the power button should work. Maybe it was more the physical pressure in that area of the housing that caused the display to come up again. At the next boot it lasted only two seconds in Ambient until the screeen switched to black. When I now boot it anew (again and again), the display and front LED both stay turned off. Possibly some flux could help. I don't have the tools at hand for now. Because the Caps Lock key also shows symptoms, I suspect the PCB to have some defect.
I won't have the time to open it at least before next week. I won't have spare parts available until then. I will be in Mönchengladbach and Neumünster but hope to find a solution before the Neumünster weekend. Currently I use a borrowed PB.
@geit I pushed - there were no changes visible. Also the turned off Caps Lock and front LED (that permanently stays off now) speaks against a (sole) GPU issue.
