Repairing a BBC micro power supply unit (PSU)
My BBC Micro PSU went pop and billowed a load of acrid white smoke, yet was still working. It was a known issue - blown capacitor. Fortunately there are kits on ebay for around £4 with the three capacitors that often fail.
This video shows a complete walkthrough of how to repair the BBC Micro power supply and, importantly, shows how to remove the power supply from its metal housing - I could not find any other videos that showed how to do this, which is why I decided to make my own.
How to strip and repair a BBC Micro Power Supply
The whole procedure should take about 20-30 minutes, although I did have a lot of trouble with the four blue/brown connectors and with sliding the black power socket through the metal housing in order to be able to slide out the board.
Thankfully, you do not have to remove anything else out from the case. The motherboard can remain in place, so once you have removed the power supply from the case you just need to open it in order to gain access to the transistors that you need to replace.
Soldering the capacitors is relatively quick, but (not being an electrician) I had no way to know if the capacitors needed to be facing one way or the other, but thankfully it worked first time. It was a great feeling when it immediately powered up without issues.