Pioneer SX-580 (dead left channels)

[VideoPoker]

Hello all. My mom just gave me her old Pioneer SX-580. When it stopped working quite right she decided to buy a new one instead of getting it fixed but asked if I wanted it, and I said sure. Anyways, neither of the left channels will work (A and B). I decided to open it and look to see if there were any lose wires, but that's really all I could do, since I know very little about amplifiers. I was wondering if this was possibly just some minor problem and if it could be fixed (by me) and if not, would it be worth paying to get it fixed.

Also, the three backlights are burnt out but hopefully I'll be able to find those at a hardware store or something.

Anyways, any help at all would be much appreciated.

 

[agger]

First welcome to AK!

I would first check the switches, toggle them. Does the left channel come back?
If not, all Fuses OK? I assume the 580 has also these STK hybrids as power amp as my 780. You can disassemble them and exchange the left with the right one. If the problem change also, you have the found the bad devil and need to get a replacement. On the 780 it's a pluged module, you need only to loosen 2 screws, no soldering required.

 

[VideoPoker]

Thanks for the welcome.

I assume by switches you mean the dials and such on the front? If that's what you're talking about then yeah I have. I also checked the fuses and all 5 of them look to be fine. Now what was that about the STK hybrids that you mentioned?

Also, I don't know if this has anything to do with it or not, but the amp has the two needles that show the power output (sorry, not sure what the proper name is) anyways there are two on the front of the amp. (Here's a picture of what I mean. SX-580)
The far left one will move for a second as soon as I power up the amp, but after that it'll go back down and won't move at all when listening to music.

Thanks for the reply too.

Edit: There are these two large black things that say Darlington power pack and underneath they say STK-0029. I take it that's what you're talking about with the STK hybrids? They look to be screwed on with silicon grease or something in behind.

 

[Pioneer727]

Welcome to AK I would clean the inside of all the pots and switches with DeOxit Then check the DC offset. It may be as simple as a dirty switch.

Ron

 

[VideoPoker]

Ok well first off, I tried switching the STK hybrids like aggar said but nothing changed, it seems to be the same. Also, when you say clean the ports and switches (like I said I'm quite inexperienced with taking apart electronics) what exactly should I be looking for? Same goes for the DC offset, I'm also not aware of what that is.

Sorry for the ignorance, heh.

 

[Pioneer727]

To learn about the DC offset go here.

http://audiokarma.org/forums/showthread.php?t=5634

For cleaning the pots someone with knowledge of the 580's will tell you how to get to the control pots and switches.

Ron

 

[agger]

Hmm, if you switch the STK's and still the left chanel is off, maybe you have a problem on the speaker switch or the protection relay contacts.