Tag: zx spectrum

Repairing the ZX Spectrum Coil

For the past few days I’ve been trying to get the DC-DC circuit working on a ZX Spectrum Issue 3. The problem was TR4 kept drawing too much current which damaged the transistor. The DC-DC circuit is really a horrible design. Even after applying the DC-DC mod which makes the circuit more stable I still …

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ZX Spectrum Diagnostic Board

After buying a few faulty ZX Spectrums on eBay which were having memory issues I decided to build a diagnostic cartridge to help troubleshoot the RAM issues. After looking through various internet sites I eventually found a schematic and diagnostic ROM by Dylan Smith. The original site however is no longer online but I did …

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