Hi everyone, let me introduce myself and ask for a little help!
Hi everyone, let me introduce myself and ask for a little help!
I approached the ZX Spectrum in 1982, at the time I was 19 and it was love at first sight! I still remember the first intervention on the Speccy with the addition of ram to bring it to 48K and then later to modify it in a "48K plus"., I spent entire days playing and programming first in basic then in assembler I was satisfied to work with this machine! I remember that I also wrote the degree thesis (pity that it was not on computer science but on artistic subjects ...). In any case, to not go on too long, 2 years ago I decided to bring my old friend back to light and immediately I had to change the membrane, then I performed the "mod" for the composite video and slowly the idea of building a new one from scratch took hold! Before getting to this point I had to procrastinate, study, document myself, find all the components and then finally I decided to undertake this journey into the memory of the 80s. And so last night my beloved Speccy saw the light with no small difficulty; a pin of an IC Socket was sunk in the plastic and did not make contact, then the voltages were not exactly the best so I went with DC DC mod and so I brought them back to perfection at +5 -5 and +12 V. fantastic not even a decimal! Now I'm sorry to immediately propose a request for help but I'm really groping in the dark, unfortunately the diagnostics suggests a "BAD RAM IC7" but from all the checks I've performed there is no actual error, I tried to swap the chips, even all the multiplexers, check all the pins of the IC Socket, change diodes, all the voltages are perfect but nothing to do ... If there is someone who can give me suggestions on how to intervene I would be eternally grateful especially if we eliminated the error. The copyright is perfectly visible, there is the audio of the speaker but it is very low and apart from this I have not yet tried to load a program but I will try. Thanks to everyone, I'm happy to have found this Blog.
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Re: Hi everyone, let me introduce myself and ask for a little help!
Hello and welcome to our forum Marper63!
I'll start a new topic in the ZX Spectrum hardware area for you. As that's a better place to discuss hardware problems.
If replies about the hardware problem can be posted in this new topic that would be great
I hope you enjoy this forum and good luck tracking down the problem
Mark



I'll start a new topic in the ZX Spectrum hardware area for you. As that's a better place to discuss hardware problems.
If replies about the hardware problem can be posted in this new topic that would be great

I hope you enjoy this forum and good luck tracking down the problem

Mark
ZX81 Variations
ZX81 Chip Pin-outs
ZX81 Video Transistor Amp
Standby alert 
There are four lights!
Step up to red alert. Sir, are you absolutely sure? It does mean changing the bulb
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ZX81 Chip Pin-outs
ZX81 Video Transistor Amp


There are four lights!
Step up to red alert. Sir, are you absolutely sure? It does mean changing the bulb

Spring approaching...