4 ms·

I have kept my Spectrum 48k and QL stored in reasonable condition but have not booted them in decades. Probably will need some work if I ever get round to them.

rwmj 1y ago
Don't just plug them in randomly! The original power brick can get out of spec (delivering over-voltage), and the voltage regulator on the PCB commonly fails. In the worst case this can end up permanently damaging other components. There's a routine you can follow to test each part, although you'll need a multimeter and some experience, and a bench power supply will come in handy as well. I'd recommend looking at these sites: https://retrorepairsandrefurbs.com/sinclair-computers/ https://retrorepairsandrefurbs.com/sinclair-computers/ https://www.retroleum.co.uk/ https://www.retroleum.co.uk/ and Lee on Youtube: https://www.youtube.com/@MoreFunMakingIt/videos https://www.youtube.com/@MoreFunMakingIt/videos https://www.youtube.com/@morefunfixingit/videos https://www.youtube.com/@morefunfixingit/videos plus Lee has a Discord where they discuss fixing old Sinclairs, linked here: https://www.morefunmakingit.co.uk/links/ https://www.morefunmakingit.co.uk/links/.
- PeterStuer 1y ago
  Thx for the advice. Will definitely measure the power bricks before plugging them in.
  - djaychela 1y ago
    Yes, do. Although I have one whose output seems OK but doesn't power the system ok when connected. They definitely were built to be cheap rather than to an engineering standard! Not slating them, times were different and every penny counted. I've got 4 spectrums here... 3 are 48k but one is original 16k....which is the most interesting one but it's the one that doesn't work!
    - rwmj 1y ago
      A modern Meanwell power supply is simply going to be safer as well as far more efficient (and smaller!) Just make sure you get the polarity right. This stackexchange question is quite good on how and why the 9VDC supply at the jack gets converted to 5V, 12V and -5V internally: https://retrocomputing.stackexchange.com/questions/2242/how-and-why-did-the-zx-spectrum-use-so-many-voltages https://retrocomputing.stackexchange.com/questions/2242/how-...

rwmj 1y ago

Don't just plug them in randomly! The original power brick can get out of spec (delivering over-voltage), and the voltage regulator on the PCB commonly fails. In the worst case this can end up permanently damaging other components. There's a routine you can follow to test each part, although you'll need a multimeter and some experience, and a bench power supply will come in handy as well. I'd recommend looking at these sites: https://retrorepairsandrefurbs.com/sinclair-computers/ https://retrorepairsandrefurbs.com/sinclair-computers/ https://www.retroleum.co.uk/ https://www.retroleum.co.uk/ and Lee on Youtube: https://www.youtube.com/@MoreFunMakingIt/videos https://www.youtube.com/@MoreFunMakingIt/videos https://www.youtube.com/@morefunfixingit/videos https://www.youtube.com/@morefunfixingit/videos plus Lee has a Discord where they discuss fixing old Sinclairs, linked here: https://www.morefunmakingit.co.uk/links/ https://www.morefunmakingit.co.uk/links/.

PeterStuer 1y ago
Thx for the advice. Will definitely measure the power bricks before plugging them in.
- djaychela 1y ago
  Yes, do. Although I have one whose output seems OK but doesn't power the system ok when connected. They definitely were built to be cheap rather than to an engineering standard! Not slating them, times were different and every penny counted. I've got 4 spectrums here... 3 are 48k but one is original 16k....which is the most interesting one but it's the one that doesn't work!
  - rwmj 1y ago
    A modern Meanwell power supply is simply going to be safer as well as far more efficient (and smaller!) Just make sure you get the polarity right. This stackexchange question is quite good on how and why the 9VDC supply at the jack gets converted to 5V, 12V and -5V internally: https://retrocomputing.stackexchange.com/questions/2242/how-and-why-did-the-zx-spectrum-use-so-many-voltages https://retrocomputing.stackexchange.com/questions/2242/how-...