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Replaced output transistors, anything to do before I power it on?

Raccoon1400

Raccoon1400

Super Member
I just replaced the outputs in my pioneer SX-3600. Is there anything I can do before I power it on so I make sure it won't blow up again?

It blew up because I shorted the collecter and emitter of an output while taking a reading.
 
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I think the people that have done and/or do technical work professionally, would say the right setup is a VariAc, an in-line AC current meter and a dim bulb tester.

That's why this equipment ends up on working benches. It's the right stuff to have.
 
Also recheck all you work for any mistakes again . Pay particular attention to any solder joints for bridging .



Barney
 
I built the tester, and connected it to my SX-535, which works fine. The bulb lit up, and the unit didn't turn on. But unit works? With my fisher 180, the bulb glowed dimly and the unit worked.
 
with my technics home theater receiver, the receiver and the bulb flash off and on. With my sx-5, both the unit and bulb are on. Did I make this thing wrong?
 
What size bulb are you using ? Try a different size .

When using the tester you should experience a glow on start up and should get dimmer . But the unit will work and as you give it more volume the bulb will get brighter .


If something is wrong the lamp will get very bright at start up !



Barney
 
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I was using a 13 watt compact fluorecent bulb. With 40 watts, the 535 powers up. Guess I'll try the one with the new outputs now.
 
Raccoon1400 said:
I was using a 13 watt compact fluorecent bulb. With 40 watts, the 535 powers up. Guess I'll try the one with the new outputs now.
Click to expand...

I would think incandescent would be a better choice..My 2 cents... Fluorecents have starter circuits.
 
With the amp I just fixed the 40 watt bulb glows brightly, and no signs of life in the unit. Guess I have some debugging to do. Any suggestions on how to go about doing that?
 
Dim bulb testers / protectors ONLY work with INCANDESCENT bulbs.

Perhaps now in this age of CFLs we should point that out.
 
When you replaced the transistors did you also replace the mica on them or reuse the old wafers ?


Did you happen to use artic silver silicone paste on the transistors? Hope not !

Check to see if there is a short to ground through the mica .



Barney
 
Oerets said:
When you replaced the transistors did you also replace the mica on them or reuse the old wafers ?


Did you happen to use artic silver silicone paste on the transistors? Hope not !

Check to see if there is a short to ground through the mica .



Barney
Click to expand...

I got a new insulator that didn't require thermal paste.
The receiver also blew two tester bulbs.
 
Raccoon1400 said:
I got a new insulator that didn't require thermal paste.
The receiver also blew two tester bulbs.
Click to expand...

What sort of bulbs? You're not still using the compact fluorescents are you?

The bulb should never blow from a bad stereo because even a dead short in the stereo is no different than connecting the bulb as it normally is in a lamp.
 
I used a 40 watt incandescent. I have the service manual, but I'm not really familiar with the procedure for diagnosing a problem like this. Guess this is my chance to learn.
 
found a resistor with no resistance accross it. Resistor was fine, desoldered it and tested, something must be fried elsewhere.
 
RossW said:
It wouldn't hurt to check the driver transistors for shorts as well...
Click to expand...

The suggestion above was the fifth post in this thread.

When outputs blow, usually something else is blown as collateral damage. You could end up damaging your new outputs if not careful to check for upstream damage.

Good luck,
John
 
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