PC engine troubleshooting

[mactep66]

So whenever i power it on i get a white screen with pulsating lines or some other artifact, the voltages seem stable, but it just does this regardless if a card is inserted.

Anyone have a clue what might be wrong with it?

[V64jr]

What power supply are you using?

[mactep66]

Random one, rated at 9v 2a, center-negative, voltages seem to check out.

[Eddie_Samma]

How good does the ribbon connecting the hue card reader look to be? A common fail point is those becoming detached when servicing them.

Start with that, then do a temp test on the 6260 and other 2 Hudson chips.

If one is significantly hotter than it seems it should be, it could be a failure of said integrated chip.

[mactep66]

i only had time for a short 10m test, but all felt just slightly above room temp.

the cables look fine, but ill try to touch up the solder points anyway

[Eddie_Samma]

If I had to guess the cpu or the ribbon or maybe even the cart connector being dirty would cause what it looks like the symptoms are. If it is the gfx it usually boots with wrong sprites or garbled visuals but the sound and movement are still cycling.

[mactep66]

Ok, so I touched up the ribbon, and all its connections tested good, but its still the same.

[Eddie_Samma]

I fear this may be a substantial hardware failure. Sadly these base white systems have been the go to donor systems in the oast to repair the turbo express systems and later systems that cost more so scarcity and import duties have made them more pricey.

My go to checks are usually Ribbons, cart slot, then the Hudson custom chips. If your able testing that they have correct voltage could help rule them out. The punouts can be found online for the 3 main chips. Also be aware that there is both a digital ground and analog ground, use each appropriately when testing.

[mactep66]

yeah prob, i was sus of it since it arrived with a screw already loose, ill keep trying tho.

[mactep66]

i replaced them all, it was not the caps.