ZX Spectrum (Issue 3)

I started coding with ZX Spectrum at the age of 12, so it wasn’t difficult to choose what I would start with to fix and refurbish retro computers. I already have quite a few Spectrums, but haven’t bought one for a while; but while scanning eBay I came across a very cheap ‘untested’ listing and couldn’t resist it. I was hoping for a complex repair that would stretch my diagnostics and repair skills.

ZX Spectrum
ZX Spectrum

On arrival it was very well packed and looked in pretty good shape. Opening it up, I found an immaculate Issue 3 board with no signs of previous repairs – how disappointing. Powering it up with a diagnostics card showed no errors, although I couldn’t get the RF output working; this is not unusual, the RF module frequently doesn’t work.

For the first update I did the standard capacitor video composite mod – this sorted the lack of a display, although it suffered from lots of interference. Again, this is not unusual and is usually fixed by changing the capacitors. You sometimes need to change a couple of transistors as well.

With the mods complete the picture problems disappeared – one of the cleanest video displays of all my Spectrums.

The only thing left was a good clean – even the keyboard membrane worked. I decided to keep this unit as close to standard as possible so didn’t change the regulator and remove the heat sync, which I would normally do.

I already have issue 2,4 and 6 versions of the Spectrum, so this adds nicely to the collection, even if it didn’t need any fixes.