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<p>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.<br /></p>
<p>Regards<br /></p>
<p>Rob<br /></p>
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<p>On 22 October 2015 at 20:45 Mark Wickens <mark@wickensonline.co.uk> wrote:<br /><br /><br />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.<br /><br />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.<br /><br />Just my 2€ worth...<br /><br />Sent from my iPad<br /><br />> On 22 Oct 2015, at 20:31, Jordi Guillaumes i Pons <jg@jordi.guillaumes.name> wrote:<br />> <br />> <br />>> El 22 oct 2015, a les 21:30, Hans Vlems <hvlems@zonnet.nl> va escriure:<br />>> <br />>> Change capacitors perhaps? Had it been switched off for how long?<br />> <br />> Months<br />> <br />><br /></p>
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