One issue I had was a dry solder joint on one of the transformer connections to the PSU
circuit board - given the weight of the transformer this is definitely worth checking.
The switch for VAXstation 4000/60 & 4000/90 PSUs (they are the same physical unit
although they have different part codes IIRC) is a 'soft switch' so power is
applied to the input stage of the power supply as soon as the cable is plugged in. I'm
not sure whether that is significant although part of me thinks that this is more likely
to cause a breakdown of the high frequency mains filtering capacitors if the machine has
been left plugged in, even if switched off.
Just my 2? worth...
Sent from my iPad
On 22 Oct 2015, at 20:31, Jordi Guillaumes i Pons
<jg at jordi.guillaumes.name> wrote:
El 22 oct 2015, a les 21:30, Hans Vlems
<hvlems at zonnet.nl> va escriure:
Change capacitors? perhaps? Had it been switched off for how long?
Months