Picture garbled - Which chip to replace?

[vicassembly]

If you had to suggest a chip to replace which would you choose?

[TheMightyMadman]

Looks like a bad RAM chip, as you can see in this blog:
http://swut.net/vic20.html

If it's an early VIC-20 with a two-prong PSU debugging RAM will be more tricky, as these have a lot more RAM chips (10 vs 4).

It could be something else, though RAM is likely. I'm sure someone else on the forum will know better than me

[Kakemoms]

Hmm.. color RAM and screen map RAM both corrupted.. unlikely... but maybe ZP corruption. Vic background and screen colors look ok, so its the clearing of the screen that fails. And that uses pointers in ZP (which is not tested during boot).

Try clipping a working RAM chip on top op the ZP RAM chip (just bend its legs in a little and put it on top of the soldered RAM chip).

Edit: Before you do that, you could also try to poke blindly into the color mem to see if the screen changes.