10 Sep
2011
10 Sep
'11
8:29 a.m.
I opened it up and looked around. Nothing looked out of the ordinary,
except when I turned it on and let it sit for a second I saw some tiny
sparks next to the solder pad of a diode and then another just half way
down a run. Just as a WAG, I assume that a capacitor has leaked? The
sparks were pretty near a 200v1200uF cap, but I don't see anything that
looks like an oily goo. I was hoping for something obvious but it isn't
looking that way.
Brian
On Fri, 2011-09-09 at 19:11 +0100, Tony Duell wrote:
It looks like the power supply to my decstation 5000/120 is shot. The
storage expansion, which is connected to the the switched C13 on the
power supply, powered up as expected but nothing on the box itself.
That power outlet is almost certainly just connected to the mains input
circuirty and doesn't sepend on the rest of the PSU working.
Brefore you go any further, I think you could check that the PSU outputs
really are dead (all of the? Just some?) using a voltmeter. The hard part
of doinf this is that fidning out what the various ouptu wires actually are.
If possible, replace the guts of the machine with a dummy load (6V and
12V bulbs) just in case a short in the rest of the machine shutting
everything down. I doubt i,though.
There was a bit of a smell, but no magic smoke :) So how hard is it to
repair a power supply for this? My soldering skills are mediocre at
That depends on what is wrong with it... You're not going to get
schematics, so oyu are verymuch on your own. And remember there are
lethal voltags (like 350V DC with a high current availability) in there,
and that much of th circuitry is most likely driectly connected to the
mains
How I'd attack this would be to open up the PSU and find/check the mains
input rectifier, maisn smoothing capacitors, chopper transistor(s) (If
that's failed, I then expect a lot of work), and the startup resistor.
But even fidning those cna be non-triivial if you've not worked on PSUs
before.
-tony