DiagROM results - Address Error

[darkhalf]

Looking for some guidance with this one. A500 V6 originally with 512KB and extended (added extra chips to 1024KB)

I've noticed random crashes, particularly when it has been running for a while, so have burned DiagROM to a 27C400 and running memory test, it gets this error (pic attached)

I'm not sure where to start with this (working out which memory chip to replace). I've turned off JP2 with no improvement. Any suggestions appreciated

thanks

 

[Pinback]

just to make sure you are not stumbling like me when using diagrom. cant speak for the current version, but diagrom had a bug in its quick or standard memtest routine, which was at least irritating. thats why the extended test routine is more reliable. afaik, this extended test routine is/was hardcoded to test 2mb chip ram. so your machine will fail all tests above 1mb.
to my own regret i wont be of any further help i assume.

 

[levo-ace]

There seems to be corrosion on theses tracks from agnus to the ram . You need to check these , and clean them up and make sure they have continuity through the board , and between either end .

 

[miggymad]

Is it my advanced aged eyesight or do the pins circled look only partially soldered?

 

[levo-ace]

After checking on amiga pcb explorer , it would seem that they only go to the trapdoor connector , not to the ram .

Amiga PCB Explorer

The Amiga PCB Explorer is a browser application that was designed to assist people in various aspects of Amiga mainboard repairs.

www.amigapcb.org