SX-1280 Transformer

[Mike Schmitt]

SX-1280 Transformer open primary? Ideas

 

[redk9258]

You should post this in the Pioneer forum. Maybe there is a thermal fuse that can be replaced. If so, a little surgery on the transformer is in order but there are some who have done this successfully. BTW you should only ask about buying / selling in Bartertown.

 

[avionic]

I recently purchased a SX-1280 Receiver. I have it with a qualified tech and he tested the transformer and the primary Is open. I need to locate a Transformer for this. I’ve looked everywhere. Going out on a limb and checking here if anyone has one for sale. The part is Bando ATT-447. Thanks in advance.

I believe the 1280 has a softstart circuit.

Theres always the " parts pirates on the bay"...

 

[Mike Schmitt]

I have tried there. Can’t find anything. Possibly getting it repaired. Just need to find the part or get mine fixed.

 

[avionic]

Maybe there is a thermal fuse that can be replaced.

The thermal fuse sets right beneath the softstart ballast resistor..

 

[Mike Schmitt]

When the transformer is opened up, it is all sealed in epoxy. Only a small hole in the center where the wiring goes. Not sure how to get in there

 

[avionic]

When the transformer is opened up, it is all sealed in epoxy. Only a small hole in the center where the wiring goes. Not sure how to get in there

Follow the brown primary wire and start chipping away at the epoxy. At this point what have you got to lose ?

 

[Tom B]

As Avionic said, check the thermal fuse under the large ballast resistor on the soft start board. And check the large 3.3 ohm ballast resistor for open. If either are open it can give the appearance of an open primary winding. Of course check the 12a fuse F01 for open as well. But if they look good and the brown lead measured with an ohm meter to the white lead of the transformer reads open, and the transformer is sealed in epoxy, you may need to wait it out on ebay, as your transformer is dead.

 

[avionic]

Tom
The schematic shows a second thermal fuse on the brown wire.

 

[avionic]

I've seen shorted output transistors that would load down the relay coil voltage . Preventing the by-pass of the ballast. Burning up the ballast and destroying the thermal breaker fuse.

 

[slow_jazz]

I've never known one of those transformers to go bad.

Not saying it can't happen but must be very rare.

Good luck...

 

[Tom B]

Tom
The schematic shows a second thermal fuse on the brown wire.

Totally agree. I am just suggesting that Mike double checks and makes sure that the transformer is open from the Brown lead to the White lead. Some techs will at times just ohm out the AC cord after turning on the power switch and read open. then they may check the fuse and see it is OK and then say that the "Transformer primary is open"

 

[Watthour]

As avionic wrote, what do you have to lose?


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