New build with recycled parts on a ridiculous budget 120cm*60cm work area

[Clive S]

The pic shows a block with the red wires connected but to my eyes the black wires are not connected as one of them appears to be in the wrong connector.

shorting the output of the PS with an amp meter would probably wreck the meter.

I doubt you have blown the caps or the rectifier. If you want to discharge them put a small value resister across the caps temporally like 220 ohms or a mains light bulb across them.

put your meter on the AC range and check the voltage on the input and output of the transformer.

Have you checked the fuse on the input?

Lets see a good pic of the PS