exxos's Atari, Amiga & retro forum

i've just been given an amiga 500+ rev 8a board
when powered up i get a grey screen and power led flashes
i've made a diag rom and replaced the kickstart with it but no difference
i've swapped most of the ics from my working a500 apart from the agnus as my other 500 is not the plus.

i'm leaning towards the chip ram, i've ordered 10 x 20 pin sockets as i have a spare 1.5mg ram expansion with 12 ram chips that should work in place of the chip ram.
not sure what else to look at apart from buying a replacement agnus for it

when powered on the caps lock led lights no flashing, gotek powers up but no activity (or on original drive) and the power led flashes with grey screen no other activity

thecaver99 wrote: 28 Dec 2021 19:32 i've just been given an amiga 500+ rev 8a board
when powered up i get a grey screen and power led flashes
i've made a diag rom and replaced the kickstart with it but no difference
i've swapped most of the ics from my working a500 apart from the agnus as my other 500 is not the plus.

i'm leaning towards the chip ram, i've ordered 10 x 20 pin sockets as i have a spare 1.5mg ram expansion with 12 ram chips that should work in place of the chip ram.
not sure what else to look at apart from buying a replacement agnus for it

when powered on the caps lock led lights no flashing, gotek powers up but no activity (or on original drive) and the power led flashes with grey screen no other activity

Stop. Before doing ANYTHING get DiagROM. Either burn yourself a copy to a 27C400 or get one off eBay. It will tell you exactly whats wrong.

If you read my post, i've already said I have diagrom burned already and there is no difference

But thanks for replying
When diagrom is in it does exactly the same thing there is no difference what so ever

thecaver99 wrote: 28 Dec 2021 20:34 But thanks for replying
When diagrom is in it does exactly the same thing there is no difference what so ever

DiagROM will work with no ram. So use the serial output. If DiagROM is completely dead you have something simple like a clock line fault or a broken trace.

Didn't think of that will dig out my serial link bits that used with my atari diag cart and hook it up, thanks

just run diag rom and captured the serial and at the end

Write: $AAAAAAAA 10101010101010101010101010101010
Read: $FFFFFFFF 11111111111111111111111111111111 FAILED

Write: $55555555 01010101010101010101010101010101
Read: $FFFFFFFF 11111111111111111111111111111111 FAILED

Write: $F0F0F0F0 11110000111100001111000011110000
Read: $FFFFFFFF 11111111111111111111111111111111 FAILED

Write: $0F0F0F0F 00001111000011110000111100001111
Read: $FFFFFFFF 11111111111111111111111111111111 FAILED

Write: $0F0FF0F0 00001111000011111111000011110000
Read: $FFFFFFFF 11111111111111111111111111111111 FAILED

Write: $00000000 00000000000000000000000000000000
Read: $FFFFFFFF 11111111111111111111111111111111 FAILED

NO Chipmem detected
- Parallel Code $fc - Trying to find some fastmem (as no chipmem found)
- Parallel Code $fb - Memorydetection done
- Parallel Code $80 - NO Chipmem detected
- NO MEMORY FOUND - HALTING SYSTEM

looks like i have no chip ram

Battery damage?

Just looking at the service manual and there are 3 x 74f ics that service the chip ram, might remove them and check them

No battery damage at all the board is clear and the battery was removed before it leaked by looks of it.
I e had a good look at the board where the battery was and no signs of corrosion and no green anywhere on the ics or other components