Fault ZX Spectrum 48k

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Barney5050
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Joined: Fri Apr 02, 2021 2:34 pm

Fault ZX Spectrum 48k

Post by Barney5050 »

Hi went to play this today and have this on start screen , doesn’t get to point where I can get keys to work , any ideas ?

Thanks
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1024MAK
Posts: 3592
Joined: Mon Sep 26, 2011 10:56 am
Location: Looking forward to summer in Somerset, UK...

Re: Fault ZX Spectrum 48k

Post by 1024MAK »

Hello and welcome :D

I’ve moved this topic into the ZX Spectrum Hardware area.

The good news is that it looks like the Z80, the ROM, the ULA and most of the RAM is working. But after doing it’s memory check and trying to set the system up, the Z80 is crashing. It could be a fault with the upper RAM.

Do you have any test gear, such as a digital multimeter? Logic probe, or oscilloscope?

And are you able to solder?

Mark
Barney5050
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Joined: Fri Apr 02, 2021 2:34 pm

Re: Fault ZX Spectrum 48k

Post by Barney5050 »

I can solder but have no test equipment unfortunately

Mark
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Tiger
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Re: Fault ZX Spectrum 48k

Post by Tiger »

I also think it is a faulty upper-RAM. ;)
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1024MAK
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Joined: Mon Sep 26, 2011 10:56 am
Location: Looking forward to summer in Somerset, UK...

Re: Fault ZX Spectrum 48k

Post by 1024MAK »

You could disable the ‘upper’ DRAM. Follow the advice in this post.

Mark
Barney5050
Posts: 5
Joined: Fri Apr 02, 2021 2:34 pm

Re: Fault ZX Spectrum 48k

Post by Barney5050 »

Ok will have a look thanks
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