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Amiga computer related discussion => Amiga Hardware Issues and discussion => Topic started by: dougal on March 03, 2012, 11:53:14 AM

Title: Trying to resurrect an A500 motherboard
Post by: dougal on March 03, 2012, 11:53:14 AM

Its a Rev 6A motherboard i have spare. 512K Chipmem and 8372 agnus A500.

It goes through the grey check/test screens and gets stuck on the last grey screen.

I tried replacing Garry and Paula and tried another Kickstart but same results. Traces look good though i did not test them and motherboard is pretty clean.

I also tried an A500+ 2MB Agnus but that did not work. Just got a black screen. I also tried pushing down the socketed chips and switching the CIA's.

Any ideas what i could try ?

Title: Re: Trying to resurrect an A500 motherboard
Post by: arttu80 on March 03, 2012, 12:40:32 PM

You may check rear of motherboard at 5-pin power connector, I once had cracked solder joint because this socket gets much action over years. So I had jamming machine, but once I resoldered it, it booted fine. Ofcourse this is just one of many possible failures. I don't think this is in any way related to custom chips, but 2Mb Agnus is really incompatible with early mobos.

Also did you have 512kb RAM expansion connected? If not, try one, because if someone made 1Mb chip RAM hack on this board, it wouldn't boot without additional RAM installed. Good luck!