[rescue] SUN IPC PSU - still not working after recap

[Ian Litchfield]

I have the same issue on my SPARCClassic. I replaced the capacitors in the
power supply and now the unit doesn’t power on. It’s pretty frustrating. It
was working before I replaced them, but I wanted to be forward since they
are known to fail.

It’s been sitting in a box all this time since it stopped working, such a
shame. Not really sure where to go with it.

-Ian L.

On Fri, Jun 6, 2025 at 09:14 Andrew Back via rescue <rescue at sunhelp.org>
wrote:

> On 06/06/2025 13:42, Jan Liška via rescue wrote:
> > Hello,
> >
> > I’ve started recapping my IPCs using locally sourced low-ESR capacitors.
> > However, both PSUs I’ve recapped so far exhibit the same issue:
> >
> > They power on for a very brief moment (about 0.1 seconds), the 5V rail
> > voltage rises to 2–3V, and then the unit shuts down. I checked the units
> > for cold solder joints and significant corrosion damage on trails but
> > found none.
>
> This doesn't help, but just to add that I've experienced the very same
> problem and come across others who have also. Hence would be interested
> to hear if anyone gets to the bottom of what appears to be a common
> failure mode. Sadly my SMPS fault finding skills are pretty minimal.
>
> Andrew
>
>
>
> _______________________________________________
> rescue list - http://sunhelp.org/mailman/listinfo/rescue_sunhelp.org
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://sunhelp.org/pipermail/rescue_sunhelp.org/attachments/20250606/fcf4d3c3/attachment-0001.html>