9 May
2012
9 May
'12
10:23 a.m.
On Tue, 2012-05-08 at 12:47 -0400, gene heskett wrote:
I hope I helped.
You confirmed that it's a good idea to replace the capacitors, regarding
to the age of the PSU. Yes, you helped.
Btw. the capacitors I unsoldered where still perfectly ok.
Not all capaictors are tested but we guess all are still ok, we anyway
will replace them.
We needed a good magnifier to see that a diode (IIRC near the
opto-coupler) had a could solder point. I couldn't see it with the
magnifier I own.
The main issue seems to be that one HER 300 (a 50 ns fast diode) for
rectification on the secondary side is borked.
After we found out this, we found out that the Behringer UB-SPSU2 is
known for this issue. Btw. it's also possible to get the circuit diagram
in the Internet for free.
The diode does cost nothing, but it's not easy to get here. No equation
diode. We found out that there's one diode IIRC >= 3A >= 200V <= 50ns
does exist here, Thomas anyway will order a HER 300. I didn't find it at
my dealer. So no mixer today, I need to test my Ubuntu Studio by
directly connecting to the Amp or using the headphone output of the RME
card.
A note. Thomas has got best equipment from Weller for unsoldering and
soldering, but even he had issues to unsolder and solder. He was near to
take it along to his employment to do it with hot air.
It's possible to do it with my Ersa C25 and a soldering tip that doesn't
cause tinder, but since it's even hard with best Weller equipment for
somebody who does such work everyday, it's no fun to repair the PSU.
Thanks,
Ralf