Pioneer Sx-1980 Help
 

I have a powering up Sx-1980, but no sound, so removed the bottom plate to see that most of the small capacitors are all swollen / bubbled, and all the plastic wrap has all shrunk on them.

I am not sure if the amplifier is worth fixing or not. None of the fuse's are blown, and lights all power up. However the relays don't click, probably because the protection circuit is toast, I am assuming that this board is the board that protects the main amplifier part of this unit.

Can some one help with some tests or ideas if this is fixable, or should i just part it out to those who need parts ?

Jase

You need to do some basic tests to see why it isnt working.
Check power supply.
Check output dc volts.

You need a schematic to go much further than that.
But you need to check output transistors.
Also need to check any protection circuits.

If it is worth fixing I would start by replacing all the electrolytics.

If anything like the 1280 i had, a killer trafo & heatsinks...

dave

http://www.diyaudio.com/forums/solid...me-insane.html
Finally a Pioneer SX 1980 is it a Blessing or Curse? - AudioKarma.org Home Audio Stereo Discussion Forums

Pioneer SX-1980 service manual and schematics | FSM ID: 64025

More than a few buttons and knobs!!!

dave

yup that's the beast, its a huge HEAVY beast too! id say 9&3/4's out of 10 capacitors on the main middle board are toast :(

Transformer is pretty useless tome, way to high of voltage.

The big silver faced Pioneers are worth quite a bit to collectors. I had an SX1250 and it fetched good money on ebay. The SX1980 was the biggest and baddest of the era.

It's definitely worth repairing.

I have repair the SX1980 for my brother 1 year ago; in the aera of the discrete voltage regulators you will find many "hot spots" through termal overloading. After replace the caps in this aeras and cleaning the variable capacitor in the FM front end the device work very fine.
My english isn't good. What means this:
...and baddest of the era.

It was one of the most powerful receivers back then.