ZX Spectrum 48k Issue 2 Acquisition
Link to the original tweet at the end of the page.
This ended up being the subject of a repair video which you can find here:
The thread starts HERE!
A NEW PLAYER ENTERS THE ARENA! This #ZXSPECTRUM 48k arrived today from ebayland. No idea if it works! (kinda hope it doesn’t) This will be the start of a thread
The top keyboard facia is loose. It also has a few kinks. I’ll have to see if I can straighten these in a vice. Oh look, held on with white bluetack.
An original membrane judging by the colour and crispy texture.
More white gum holding on 2 of the feet. One foot is missing altogether. This has a test sticker dated in December this year! A time traveling speccy! That date could be 21,81 (neither possible, 81 was the year before this was made) or more likely 87 or 89.
First look inside. The membrane ends are in good condition, no cracking. It’s an issue 2 board, and at first glance it looks clean. Nothing is missing.
Bottom of the board. Some of the solder up the top left there looks dull. I’ll keep an eye on that. Some of these original solder joints are really starved of solder. Same all over the board. Must have been rationing solder on that day in the factory.
First pic is the power socket. Look like they’ve been reflowed at some point in the past. Different colour solder and the flux hasn’t been cleaned. Second pic is the ear and mic ports. Similar story there. Probably lack of solder from the factory lead to these cracking.
And here we have our first clear signs of repair. The voltage regulator joints look really bad. Possibly cracked.
On the other side we can see this has clearly been repaired by a plumber. With a blowtorch. Blindfolded. I’m very glad I didn’t just plug this in. On seeing this I grabbed a meter and measured between ground and the left leg.
According to the amazing Joulesper Coulomb this should read over 120kohms. Probably this reg is bad, but it could be something else. Looking at the state of the work I’m going to guess is this that’s bad, but that other things have been taking down with this.
TR4 and TR5 look original. I’ll have to check these later.
All the caps are original. If I get that far I’ll be replacing all of these. At nearly 40 years old I imagine they’re getting a little dry now.
Is this factory? Anyone know? Did sinclair use earth insulating tube? That solder blob on the cpu looks very suspect too.
Hmm, the other side looks equally scabby. And that resistor also looks really poorly installed. I have a feeling this is not factory either. Or if it is someone was having a lazy day at Sinclair that day.
Well I’m going to order a new voltage regulator, probably a modern traco type to cut down on heat, and put this away for now. Before I do I’ll put this cover on a vice.
Much better! Sits nicely on there now. Hope you enjoyed that journey with me. I’ll revisit this thread with updates as they happen
