A500+ grey screen problem

[murQla]

So, i have this a500+ that had first green screen error, got that fixed. Cleaned all the corroded parts and replaced data path chips (u10-u13). Replaced all memory chips. Got it running with diagrom 1.2, all tests passed flawlessly.
But when trying to run with normal kickstart, it just boots to light grey screen or black.

I have tested it with kickstart 1.2, 1.3, 2.04, 3.1.4. U37 has been replaced, gary socket replaced, traces checked from corroded area, paula, gary, cpu, cia chips replaced from working machines, all sockets resoldered but nothing helps. Any ideas because i'm running out of ideas.

Any voltages to check? I just have multimeter, i dont have oscilloscope.

[cpiac64]

new fat-agnus socket?

[jbilander]

Light grey indicates CIA error or ROM corruption. Black is No CPU detected, or ROM error, or CIA.

It sounds like you have problem with the ROM or the CIA's or the sockets/traces for them, try swapping the CIA's if you haven't tried that already.

Amiga Boot Sequence and Colours
http://www.lemonamiga.com/forum/viewtopic.php?t=13978

http://wiki.classicamiga.com/Amiga_b...r_code_colours

https://www.amigapcb.org/ is a nice resource for troubleshooting and checking traces.

[murQla]

Fat-agnus socket is also replaced, problem stays...

All custom chips has been swapped from working machine and tested in working machine so problem is somewhere in the mainboard. CIA's swapped etc...traces checked with multimeter, both CIA and ROM sockets are still originals so maybe i'm replacing those next.

What i noticed when checking some voltages, _reset line jumps up to 7 volts sometimes and then again after reset it stays near 5 volts and suddenly it's again 7 volts, i don't think that is normal?