22 Oct
2015
22 Oct
'15
10:02 p.m.
My experience with mains filtering capacitors is on the MicroVAX II, which is
somewhat older, but in that case a failure of one of these capacitors causes
smoke and smell, but doesn't stop the PSU working. I don't know if a more modern
PSU would stop working if one of these capacitors failed, but I think you would
know that it had failed.
Regards
Rob
On 22 October 2015 at 20:45 Mark Wickens <mark at wickensonline.co.uk> wrote:
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