SX-780 Transformer

gmonstah

Member
Hi all,

Just picked up a Pioneer SX-780 at the thrift store. It needs a new transformer.

Writing on the present one:
Bando
BE91h-0001
ATT-512
A-BE11-THZ

There is a used one available - you can guess where -) It is also from an SX-780

Bando
BE91h-0001
ATT-512
But the last line is B-BE11-ZLH

Does anyone know for sure if that last line matters?

Thanks
 
You're positive the transformer needs replacing? Are you getting no voltage on the secondaries? Fuse blown anywhere?

If its defo the transformer that has gone you may have luck pulling off the outer layer of the trafo and replacing the thermal fuse.
 
Yes, Slimecity, I am certain. And I wish it was an open circuit.

It blows the 4amp fuse F4 and the primary is shorted.

Thanks
 
The last line is of no importance. It's an internal BANDO # for dating and other extraneous info.
 
It blows the 4amp fuse F4 and the primary is shorted.
I have to ask, what do measure as far as ohms on the primary leads(BRN,WHT)? It is supposed to be very low ohms.
usually if the transf is toast it is open primary.
One last thing to try is isolating the secondary wires, (going to have to remove them anyways if you are going to change the transformer) and then try one more time. A shorted secondary will also blow a mains fuse.
Remove the transf red wires from terminals 17,18 and pull fuses F1,2,3,4, one more fuse test.
C1 could be another cause for the fuse to blow.
Here's hoping it is a damn STK-0050
 
Before posting I removed one primary wire from the fuse board and measured the resistance accross the primary. Less than .001 ohms, although I doubt my meter is actually that accurate.

Still think the transformer does not need replacement?
 
Less than .001 ohms,
Does not sound right to me.
I have no idea how you can even measure 0.001 ohms with your meter, is this a typo, the test leads and contact resistance themselves would indicate way more than that. If I compare with my Fluke37, shorting the test leads together at the probe tips, I usually get 00.4 ohms on the 300 ohm FS setting. What's wrong here?
 
You'll have continuity through the primary but you should check the case/metal for any shorts through the primary?
Same with the secondary.
 
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