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Studio Standard by Fisher RS-1035 receiver

I got a Fisher RS-1035 in fantastic Condition,but today after two hours of playing the sound was suddenly gone and there was none anymore ? The lights are still coming up but nothing else is happening !

Re: Studio Standard by Fisher RS-1035 receiver

Likely the hybrid (STK...) amps of the Fisher are defective. If the heat transfer paste dried (after decades) these hybrids develop hot spots causing the destruction of the whole hybrid.

So if you are one of the poor guys that got a hybrid amp based receiver the best thing you can do:
1. Do NOT power on the device. Chance is skyhigh that you kill the hybrid(s) even if they were ok by now.
2. Open cover, take off screws that fix the hybrid(s) to the cooling heatsink.
3. Bend hybrid forward (without breaking pins) and remove old heat transfer paste with a tissue with isopropyl aclcohol, use a Qtips for fine cleaning.
4. Put fresh heat transfer paste on the whole surface of the hybrid e.g. with the help of a knife blade.
5. Bend the hybrid back to the heatsink and fix the screws.
6. Still do NOT power on device. Recap all capacitors in the stage before the hybrids, this is the board the hybrid(s) is/are soldered to (in the Fisher it's a separate board)

Now you can power on device, and if the receiver plays, chance is high that the original hybrids will last. At least until you have sold the receiver on Ebay. :-) You do not really want to own a hybrid based amp, do you ?!?

While a broken amp transistor and a few driver transistors can be exchanged for a handful of dollars / euros the original Hybrids of retro audio are not available any more. New hybrids are China clones and are rare (some can be bought via USA or Hongkong, only). They are costly, minimum 15,00 each thus on a Fisher RS-1035 you'll invest 30,00 on parts in advance without even knowing the outcome of this adventure.

When I buy vintage hifi of early 80s at Ebay my first look is for model's service manual to check that it has NO hybrids. A power transistor based amp stage is much more heat resistant, and service is easier and cheaper.