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Pioneer SX-580 Left Channel Problem after nose-dive on floor

Hi, I hope somebody can help me.

I have a Pioneer SX-580 that I bought new back in the '70's. Last year, because it was on an unstable table, it took a nose-dive onto the floor. I fired it up to make sure there was no damage, but smelled something burning in the unit. I immediately turned it off and set it aside.

Recently I plugged it in again to see whether I had imagined the smell, or maybe it had a miraculous healing (it's Christmas - they say miracles do happen, but no such luck) only to find no sound at all coming from the left channel at all, in all modes (AM, FM, Phono or Aux). I found the fuse for the left channel blown. I replaced the fuse with another 4A and turned it back on to see if it worked. What I got was a loud hum out of the left channel, no audio at all aside from the hum, meter went to full scale which bled down slowly when the power was turned off. Right channel worked fine.

Any ideas?

Thanks.



Jim Libert's picture

Re: Pioneer SX-580 Left Channel Problem after nose-dive on floor

4 amp Fuse? That seems pretty large I would guess it would take a 2 to 2.5 amp fuse. Might want to recheck in manual or the on the back of receiver. wrong size fuse could case a lot more damage if it ever trips again.

karodimitrov's picture

Re: Pioneer SX-580 Left Channel Problem after nose-dive on floor

Check the board for cracks. Submit forced ground of the left channe of end tier of the amplifier.

Re: Pioneer SX-580 Left Channel Problem after nose-dive on floor

Thanks..

I'll check it out.

jbl

Re: Pioneer SX-580 Left Channel Problem after nose-dive on floor

Everything looked good as far as I could see. I swapped the two STK-0029 Darlington Amps to see if the problem would go to the other channel, or if there was a problem elsewhere on the left channel circuitry. When I changed the power modules, the other channel had the problem the left one had. So I ordered a new STK-0029.

karodimitrov's picture

Re: Pioneer SX-580 Left Channel Problem after nose-dive on floor

OK.Then the problem is fixed.
Merry Christmas!!!