sony dst hd100a
I checked the supply voltage,
Fuse is still intact (continuity check)
Opto-isolater on primary side is getting 120V, secondary side 0 Volts
Well i can't tell if anything else is wrong on the secondary side without power.
4 pins on the primary side of transformer same voltage reference from Ground
No voltage anywhere on secondary side of the power board.
No physical signs of damage on other components although brown smoke marks can be seen on top of the casing...
(I did replace a leaky capacitor on the primary side)
Service Center can't supply replacement part for just the transformer, which is frustrating but understandable i guess.
A SD box costs around AUS$50 and a replacement board for this unit costs the same.
go figure...
Added after 13 minutes:
Was reading here about someone elses problem
https://groups.google.com.au/group/sci.electronics.repair/msg/58392eab215a70dc
"It is likely that an internal thermal fuse buried in the transformer's
primary winding has failed. This being the case, it should be an easy job to
measure the secondary of the transformer with an ohm-meter to determine its
configuration. I would expect the most likely to be a single centre tapped
winding, in which case, your meter will read pretty low ohms between all
three secondary terminals.
Have a look to see if there is a bridge rectifier, and two smoothing caps.
If there is, then the centre tap will be connected to system ground, and the
bridge will be producing a negative and a positive rail, with respect to
ground. You can get a pretty fair idea of the secondary voltage by looking
at the voltage rating of the smoothing caps following the bridge. Take about
20% of that voltage, and then multiply the result by 0.7. So, if caps rated
at say 25v, take off 5v = 20v and then multiply that by 0.7 = 14v, so
transformer would likely be rated either 12v - 0 - 12v or 15v - 0 -15v.
There may well be 12v regulators like 7812 and 7912 following the bridge,
and 20v input would be a good figure for these. "
Is this approach worth considering?