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Stedy · 08 July 2012, 16:39

Hi,

In order to test an A500 memory expansion, I dug out my A500. Powered it up, only got a black screen.

Need some advice on what to try next.

I'm using a 90W picoPSU to power it, there is 4.90V at the MC68000 and some of the logic chips. Though I have a black screen, the composite video output has a video signal, with no content so the video timing works.

Removed, cleaned and reseated all socketed ships. Removed all RAM expansions, floppy drive does not seek (checked the cable is correctly inserted). Was looking to re-cap this but removed a tested the main power supply caps, all tested Ok for capacitance and ESR.

It's a Rev 6 A500 with 512K RAM, nice and clean too. There is no RTC on-board, that is on the RAM expansion, which has no leaking battery.

Suggestions please?

Ian

08 July 2012, 16:39	#1
Stedy Registered User Join Date: Jan 2008 Location: United Kingdom Age: 46 Posts: 733	Dead A500, need some advice Hi, In order to test an A500 memory expansion, I dug out my A500. Powered it up, only got a black screen. Need some advice on what to try next. I'm using a 90W picoPSU to power it, there is 4.90V at the MC68000 and some of the logic chips. Though I have a black screen, the composite video output has a video signal, with no content so the video timing works. Removed, cleaned and reseated all socketed ships. Removed all RAM expansions, floppy drive does not seek (checked the cable is correctly inserted). Was looking to re-cap this but removed a tested the main power supply caps, all tested Ok for capacitance and ESR. It's a Rev 6 A500 with 512K RAM, nice and clean too. There is no RTC on-board, that is on the RAM expansion, which has no leaking battery. Suggestions please? Ian