To me, & from the view given, the caps look OK.
BUT - they may be bursting through the bottom, or just be going bad without
visible sign, yet. Given the problem, a good start would be to change the
caps, and, if possible, monitor the appropriate rail while trying to
replicate the fault..
Do a careful visual check of the solder joints also while wobbling the
topside components. I. came across a dry joint the other day that was
invisible, but showed up by moving the component slightly. Or maybe it was
the resistor that was faulty but resoldering it fixed the problem. I'd of
replaced it anyway if it had been something important.
I guess in this case it may pay to check any caps around  the reset chip.
It could be making things more sensitive to voltage variations. Same goes
for any compensation or feedforward caps around the controller chip.

RP



On 10 August 2017 at 18:24, Chetan Bhargava <cbhargava@gmail.com> wrote:

> > Make sure you can try to ascertain, why the diode or diodes fell over.
>
> Maybe one summer I overloaded the 380W power supply with 8x 40W (12V)
> bitcoin miners. Heat and overload may have killed it.
> +5VSB works ok. I should have checked the outputs on scope before
> removing the diodes.
>
> >
> > Just replacing, the diode and not much else, without checking lots, can
> > cost you.
> >
>
> +12V rail uses two STPS30L60 (2x15A common cathode) diodes connected
> in parallel. One shorted (1/2 internal diode), other one is ok.
> Checked for shorts on all semiconductor parts and supply rails.
> 5V diodes are ok.
>
> > Sometimes the **actual fault** isn't where the fell over bit is.
> >
> Any troubleshooting pointers welcome.
>
> > Also remember to bleed ALL caps before working on the SMPS, these are
> > lethal beasts too!
>
> Yeah, I agree. I haven't checked if there are any bleeding resistors
> on the primary caps.
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