Spectrum 48K Upper Ram Fault

hatman72
Posts: 27
Joined: Fri Feb 12, 2021 12:59 am

Re: Spectrum 48K Upper Ram Fault

Post by hatman72 »

Ha, typo - good spot!!
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1024MAK
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Re: Spectrum 48K Upper Ram Fault

Post by 1024MAK »

I was wondering, but as you said it was working...

Mark
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hatman72
Posts: 27
Joined: Fri Feb 12, 2021 12:59 am

Re: Spectrum 48K Upper Ram Fault

Post by hatman72 »

Hi Mark

Yes, all working. Thanks so much for your help and advice.

I think I know what was causing the problem too. I have two power supplies; one is a variable voltage one and the other is a Sinclair UK1400 that was faulty. As the Sinclair PS was faulty I hadn’t been using it, but I repaired it and must have used it when the speccy came back to life. When I picked up the variable voltage power supply today I noticed it was set to 12V, so I suspect I had been over doing it. I was probably lucky I didn’t do any serious damage!

It is working well on both power supplies now. I still suspect the ULA is iffy as it has a tendency to go black-and-white every so often, can crash after a while if I don’t have a heat sink on it, and the diagnostic tests regularly tell me the ULA is faulty. I’ll probably get a new one but I didn’t want to spend the money unless I had sorted the RAM out, and that seems to be ok now.

Cheers!
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