Problems with kick v1.2 rev. 5 A500 mobo.

[Oldsmobile_Mike]

From the second picture I saw a metal clip over the Agnus chip, probably for forcing it onto socket: I never seen such thing in any Amiga 500 before.

AFAIK this is a C= fix due to all of the Agnuses (Agni?) popping out of their sockets when going over a speedbump leaving the factory.  It's mentioned in many places around the web.

As others have said, clean and reseat all socketed chips, connectors, inspect caps, try a different PSU, etc.  My bet is on a failing ram chip.  Good luck!

[Oldsmobile_Mike]

Not quite - this is a rev5 board which uses 256Kx1 RAM chips (i.e. each chip has 262144 words, each word being 1 bit, and since we have a 16 bit data bus system 16 such chips are required to complete a RAM bank).
So every single word in RAM is spread across all 16 chips (each RAM chip contributes 1 bit). Since the flaky pixels are 16 pixels apart with perfect periodicity, if it's a RAM problem it's on a single chip.

Nothing else to add, I just want to say for someone with only 14 posts on this forum... please post more info like this, more often!  Cheers!