Classic checkerboard/repeating horizontal lines on initial boot for about 10 seconds

[JRL]

So I've been recapping another MLA board member's Classic I board, and an issue that I've encountered after the recap was finished is the following. This behavior apparently happened beforehand to at a more frequent degree.

About every once in a while (1 out of 15 boots or so) I get either the checkerboard or a pattern of repeating ~4 pixel wide horizontal black and white lines. After 5-10 seconds, the Classic chimes and boots as normal.

I know checkerboard is a relatively common issue with unrecapped Classic boards but has anybody seen this particular manifestation of the issue before? The board did have cap leakage that stained the sound chip legs but I cleaned it all off and otherwise the recap was uneventful.

 

[OsvaL]

For what I read, even if you recapped your logic board but didn’t wash it, the electrolytic fluid from the leaked caps can display some erratic behavior. The recommendations are to wash it on a dishwasher or under the sink, wait some days to make sure everything is well dried and then clean all the main active components (chips, ROMs, etc.) with isopropyl alcohol.

 

[JRL]

Board has already been lightly washed and thoroughly IPA cleaned but I’ll do it again, ty! Because this isn’t my board I would prefer to keep the dishwasher to a last resort.

Was mostly looking to see if anybody’s seen this particular version of the issue before.

 

[JRL]

Reseating the ROM seems to have fixed this issue.

 

[Garrett]

I'm the owner of the board - I didn't see this until now, but thought I'd respond just in case this helps someone else in the future. Below is a picture of the pattern displayed before the machine would chime and boot. Sometimes it would boot instantly, other times it'd boot 15-30 seconds after flipping the power switch, and other times it'd take 30 minutes or more for the machine to boot. Before removing the logic board to have it recapped, it seemed to be working fine for the most part.



Here's a video of the behavior:

 

[bibilit]

Bad capacitors on the Analog board side ?

pretty common. 

 

[JRL]

Bad capacitors on the Analog board side ?

pretty common. 

Definitely a good suggestion - this board behaved the exact same way on my Classic (as well as my CII) before I reseated the ROM, so it wasn't an analog board issue.