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Making a good Spectrum +2A from two duff ones

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 desoldered those chips and put in sockets.


I've ordered more 'new old stock' ram chips, but they've taken an age  to arrive and I didn't need them anyway, one of the sets of ram chips worked perfectly.

I recapped both boards, which I now believe in doing as a matter of course.

Surprisingly it took very little work to put together a working board.


After a scrub, the good case looks fantastic. I didn't mess with its keyboard or tape mechanism as all seems fine with those.

This is a ram test, which I left running for a long time and it showed that everything is fine.


The final job was this audio mod. Loading programs and games from my ZXDUINO into +2's and +2As does work if I use one of those car tape converters (as you can see above) but it is a little flaky. (Or perhaps my adaptor isn't very good quality. Either way it all feels a bit makeshift and doesn't work every time.)

You have to cut one track and add one wire.



After that, with the right lead you can plug the spectrum into a powered speaker and a ZXDUINO at the same time, and both work perfectly.


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