The second PSU is the same model as the first and I went about its refurbishment in the same way.

Firstly, I removed the capacitors. Here was the first problem. One of the smaller capacitors was leaking. Straight over to RS components to see if I could find a replacement. Bingo, next day delivery! Amazingly I found a capacitor of the same diameter with the screw terminals on the same centres with the same screw thread. Marvellous.

I tested the other caps with my capacitance meter and they all looked feasible. I then brought the up, one by one on my bench suply with the current fixed at < 20ma. As each one stabilised at it correct working voltage, I noted the leakage current and this was typically around 0.6-0.8ma. That’s not bad at all for 40 year old caps.

Next the whole unit got a good dust, the terminals and fuses were cleaned with a wire brush and everything was reassembled prior to testing.

On of the wires running from a rectifyer was showing signes of bad corrosion so I made a new cable up with new connectors and fitted that.

I went through the same tests with car tail-light bulbs as I had for PSU1 and they lit up beautifully.

Two down, one to go.