Powering up a 20-year old MicroVAX II

[Tony Duell]

> In sending Roy the information on the markings I omitted what looks like a
> "~" after the 250V marking (the casing fragment is damaged in that area), so

Almost certainly the mains filter capacitors then...

> the caps are probably rated for 250V AC. I can also see an X2 marking on one
> of the caps (the other one is too damaged to see). As the damage is indeed
> to two caps on the mains filter, I have purchased replacements which I will
> be fitting this weekend.

OK. If you replace like with like (same 'class', rated for 250V mains [1] 
and about the same capacitance value) you should have no problems.

[1] Most filter capacitors sold in the UK are good for thsi, for ovious 
reasons.

> 
> The rest of the PSU *appears* to be in good condition but I do not have
> anything to test ESR with and I do not have a variac or the knowledge of how
> to use one, so I am unsure whether I should attempt to connect the PSU to
> the mains again or whether I should attempt to switch it on. If I do feel
> brave I will only connect a load that I do not care too much about.

Personally, I would connect it to the mains with  dummy load (car bulbs 
or simuilar). I think it'll be OK.

-tony