A500 Bootup issues

Hi All,

Brought an A500 down from the loft over the weekend but having a few peculiar boot problems, which were in fact present before I put it up there if my memory serves me.

It's an A500 with the 6A board inside. It has a 3.1 kickstart ROM v40.86 and a memory/clock expansion card installed.

When booting, I get the Guru error code 8000 0004 briefly before the purple disk animation screen. It then crashes sporadicly seemingly at random when running games or workbench.

If I remove, or turn off the expansion card (it has a little switch on it) the system doesn't boot at all, the power light blinks faded/full green, and on occasion it spits up Guru code 8100 00FF, but mainly just a black screen with little white flashes on occasion.

I've taken the case apart and all looks clean and organised inside, I have reseated the ROM chip and given all the others a firm press - but still behaves much the same.

Any further advice on what might be causing the grief would be greatly appreciated.

Thanks,

Robert

[hooverphonique]

clean all socketed chips and their sockets.. they oxidize when stored..

Thanks for the tip, I shall do just that.

Can I ask what chemicals / materials / tools are best for cleaning such things?

Also is it only the large socketed chips which come out? Or can I do the same with CPU and RAM?

[voyager_1701e]

My thought was the same....clean the chip legs and sockets. A poor connection with the system ROM can cause random issues I've found. Many older 500's I've pulled out have tarnished or oxidised chip legs. Just use cotton buds and Iospropyl Alcohol, and a soft toothbrush can also be helpful with the sockets.

Thanks, I'll give this a going over in the next couple of days and report back with any progress.