Macintosh Classic black and white pattern on start up?

[Sanxion]

Hi all,

I have come into possession of a few old Macs and as I know nothing about them, I hope you guys can help!
The first displays a rather interesting patter on start up. Please view the image and give me your thoughts.
Thanks.

 

[VeryVon]

Here's a place you can start on the checker pattern:

Repair Mac

 

[Timo W.]

First, remove the battery! This is not the cause of the problem, but it can completely destroy the mainboard beyond repair if left in.

Second, a full recap is needed. The checker-board pattern is caused by leaked caps on the main logic board. On the Classic, pretty much all caps on the analog (power) board leak as well and also need replacing.

 

[AndyO]

Both my Classic and Classic II had this problem, and in both cases an ultra-sonic clean of the logic board and a recap resolved it.

 

[olePigeon]

Why were caps made in the 1990s so terrible? I have stuff from the 70s and 80s that are perfectly fine, but stuff made in the 90s just vomit all over everything.

 

[Timo W.]

Probably because the surface-mounted electrolytic caps are just a bad design in general.