[rescue] Help me rescue my Sun Ultra 10 (2x)

[Alexander Jacocks]

On Mon, Dec 15, 2025 at 11:49 AM Dave McGuire via rescue <rescue at sunhelp.org>
wrote:

> On 12/15/25 11:37, HP van Braam via rescue wrote:
> >> When doing the visual inspection, are you checking for bulging, or
> >> just
> >> leakage?  I've seen plenty of caps visibly bulging without any
> >> leakage
> >> apparent, but if you don't know to look for it it's easy to miss.
> >
> > I was looking for bulging, or broken relief cuts in the top. I didn't
> > see any but maybe I don't really know what I'm looking for. That's very
> > possible. :)
>
>    If the "splodey lines" have opened up, there will usually be a much
> larger mess.  When that happens, it is often violent.
>
>    One thing to watch out for, and we see this at the museum all the
> time, is leakage *under* electrolytic capacitors that is not visible
> until you actually remove them.
>
>    One way to check for this without actually removing them is to heat
> one of their leads with a soldering iron.  If you get a whiff of fish,
> that's amines in the electrolyte.


Also, shining a light at the PCB at an angle can reveal otherwise hidden
venting, as the residue is more matte than the usually glossy PCB surface.

- Alex
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