PCjr white screen solid *buzz* from speaker

[gobabushka]

Ok, so after a lot of googling, I found out that the power supply board is a-ok. So the issue must be in the motherboard. I have stripped the machine down to the bare minimum. (no sidecars, no floppy or controller, no memory expansion, etc.) But all I get is a white screen with the buzz noise on the monitor. Where should I start checking? Thanks!

and how do I remove the floppy tray WITHOUT breaking the tabs?

 

[Maverick1978]

Just pull the tray out - it'll come! Trust me... It'll only break if the plastic overall is REALLY brittle (like mine was, with cracking plastic in the main part of the casing)

So far as the PCjr white screen, I don't recall off-hand what that means, but you can download the Technical Reference from my site.

I did see where a user on Mike Brutman's forums had the exact problem and found a short in his sidecar connector which caused it. There is a similar thread here on VCF.

 

[gobabushka]

Thanks I got the tray out, and the motherboard. I found the issue, there is corrosion along the rightmost cartridge port traces. What would be the best way to repair those? Or some way to disable the port all together and repair the traces later.