23 Oct
2022
23 Oct
'22
9:18 p.m.
I'm working on cleaning up a bit of battery leakage in a MicroVAX 3100
Model 10 and while it's apart I decided to look inside the PSU (an
H7822-00).
It's nice and clean inside with no bulging caps. What it does have is an
X2 capacitor, as shown here: https://photos.app.goo.gl/dpdqJ3tuGfsRDR3Y6.
It doesn't appear to be damaged and I can't see the word "RIFA" on it
anywhere but I can't see two of the sides because of other components
that get in the way.
So does anyone know for sure whether it is a RIFA brand or not, or do I
have to desolder it to be sure?
Antonio,
It does look rather like the troublesome RIFA capacitors that come in
transparent / slightly yellow cases. However, it seems to be lacking the
usual tell tale cracks.
If it is a RIFA, the worst it will do is create lots of smoke and stink
the place out. This is not a big deal compared to the six/ten 1800uF 25V
electrolytics in H7821/H7822 power supplies. If these are not already
leaking (look for a ring of brown goo around the base, sometimes only
visible after unsoldering them), they are very likely to start leaking
soon, even more likely if the power supply has not been stored in it's
natural orientation. These can do a lot of damage to the power supply
and anything else the goo gets on.
I would prioritise sorting out the ten dodgy electrolytics and deal with
the suspected RIFA afterwards.
(I found that the top board in a H7822 is identical or nearly identical
to the single board in a H7821)
Regards,
Peter Coghlan.
Thanks
Antonio
--
Antonio Carlini
antonio(a)acarlini.com