Ram chips?

[Moroder]

Hi, my amiga 500 has given me a green screen, and the LED flashes 10 times. From what I hear, this is caused by an error in the ram.

Where can I get some replacement chips? Thanks

Edit: Found these on ebay, I guess I could just buy 4 and piggyback 'em?

http://www.ebay.co.uk/itm/SIEMENS-HY...sAAOxyRhBS6agJ

[shaf]

Do not piggyback ram chips, just remove the older chips and replace them.

[Toni Wilen]

Has bad RAM chip ever been (except in some very rare situations) the reason for green screen?

Yes, it means chip ram error but more common reasons are:
- bad Agnus socket
- bad CIA (stuck ROM overlay signal)
- bad connections/bad TTL chips between Agnus and RAMs.

[Moroder]

Originally Posted by Toni Wilen

Has bad RAM chip ever been (except in some very rare situations) the reason for green screen?

Yes, it means chip ram error but more common reasons are:
- bad Agnus socket
- bad CIA (stuck ROM overlay signal)
- bad connections/bad TTL chips between Agnus and RAMs.

Thanks - I see. I did remove agnus and cleaned her up, and put her back in, still same problem. I removed all removable chips and did the same.

How do I check for bad CIA signal etc?

[Prosonic]

Originally Posted by Moroder

Thanks - I see. I did remove agnus and cleaned her up, and put her back in, still same problem. I removed all removable chips and did the same.

How do I check for bad CIA signal etc?

you can swap the 2 cias with each other if the problem stays it more than likely not the cia

im repairing an a500 with this same issue sometimes the TTL logic 74ls244's can cause it but not often, I just ordered ram off ebay ive tested all the customs in another pcb and they are fine

[idrougge]

Indeed it was the LS244s (or 373s) in my A500+ that caused the green screen, or rather the connections to those chips.