I have three Powermasters, one slightly newer, with PVC flex (old colours) and two older, with woven covered rubber flex.
Tested the newest first (none have been used for many years), plugged in and powered up, tested the outputs with multi meter, all as expected. Suddenly a fairly loud bang, the unit died and much magic smoke poured out of the vent slots. Oh. Not my area of knowledge, but blown capacitor?
On to the second, which is the one with a newly replaced mains lead. Powered up fine, but an immediate 'ozone' smell. No matter, all outputs tested perfectly. A small 'pop' but still working, so power off. Another capacitor about to expire (or explode)?
The third also requires a new mains lead, which is straightforward, and I imagine I'll be able to replace capacitors if the value is on each, and I can access them. Is that diagnosis likely to be correct?