New Stuff For Old Stuff :: Blog

I 've had two black Spectrum +2As boxed up for many years. I think both may have been car boot sale finds at a time when I was using a grey +2. One has never worked properly, one did. I used it a bit, had it repaired at some point (it has the repairer's sticky label on the bottom, I remember taking it there, but I don't remember what the fault was or what he did.) When I plugged them both in recently, the latter one worked for a little while but then developed vertical stripes. I've written a separate post about checking out and working on the power supplies . As one of the cases was mint, and the other broken, I decided to take the best from both and hopefully end up with at least one working board in the good case. (and possibly a second working board, or at least spare components.) One board already had the memory chips socketed. The other had them soldered directly to the board, and I think these were the suspect set, but the best-working board generally. I

I 've had a project going to make a perfectly-working and perfect-looking Spectrum +2 from two non-working ones. One (a car boot find from many years ago) has never worked, the other I bought and used quite a bit in the 90s. When switching it on again recently it ran fine for a little while and then vertical stripes appeared. I'll write separately about getting a working board from these two and putting it in the best case of the two. Because of that new vertical stripe problem, I checked out both PSUs, which have +5v, +12V and -12V. (Though the -12V is only used for the serial out I think). Both measured fine except for the -12V. On delving deeper I found some disturbing things. In both cases it appeared that this fuse had blown. It turns out that although this one looked blown at first glance, someone has soldered wire across it. I don't know whether this is fusewire of the appropriate rating. That's connected to a low-resistance, high wattage resistor

This is the finished project. As well as being the size and shape of a house brick, it used to be the same weight as one too. It ran hot, and it's risky to depend on a supply that's decades old. I'm sure that the credit goes to Neil at Retro Man Cave . I'm pretty sure I saw this upgrade in one of his videos and then discussed it with him, although I can't find the exact video now. Ms Mad Lemon has also done the same thing , so credit to her too. I have three Amiga PSUs and they're all different shapes and sizes. This is my largest one, and it's the one that is the right size for the Mean Well power supply which is recommended for this project. Further below is a shot showing the part number. It happens to have +5v, -12v and +12v out ,which is exactly what the Amiga needs. It also fits this case snugly. Almost as if it were designed for this job! I bought the new supply a year ago, but couldn't get into that plastic case. The screws are a