Weird A500 problem

[Everblue]

Today I got 2 x A500 machines and I was testing them out. One worked 100% ok but the other wont read the floppy drive. When I switch the thing on, the "Insert Disk" icon appears. I insert a floppy disk (which worked fine on the other machine), and after three 'clicks' the "Insert Disk" icon appears again.

I have used a number of (tested and working floppy disk drives) as well as cables from the other machine. All with the same result. This means that the A500 is at fault. I looked at its motherboard but I can find nothing 'strange'. Anyone knows where could the problem be?

Thank you in advance,


E'Blue

[Everblue]

Metalguy66 wrote:
Swap both the 8520s (u7 and u8) from the working machine to the non-working machine and see if the problem goes away.. If this corrects the problem, swap them BACK one at a time.. When the problem reappears, you know the chip you just installed is bad.

Did exactly that .... problem solved! I have one duff CIA chip.
Thanks a lot for help!