New in search of some guidance and help re:Repairing some old recivers

[Bitter]

Hi, I've managed to acquire a few old but not old enough to be valuable or high end enough to be well documented receivers over the few short years on this earth.

I have a Hitachi SR-603 and a SR-304 with some scratchy pots and flaky switches that I'm going to try some Caig De-oxit pot and fader cleaner/lube and report back on. I'm sure they'll be fine and everything else works except some burned out back light bulbs. I love my Hitachi's, they sound great to my tin ears.

What I came here for actual help with is a Pioneer SX-2900. It has the usual 4 speakers spread across left and right channels with A and B channels as well for front and rear or whatever you wish. My problem is that ONLY A or ONLY B work, never both at the same time. I've sprayed some De-oxit into the switches and that fixed their flaky/scratchy problem (had to play with them to get them to work) but not the problem with only A or only B working. I'd like to be able to use more than 2 speakers with it, so I need some help trying to diagnose and then if I can repair this. I've read the owners manual and it states:

NOTE:
No sound will be heard through the speakers when both A and B are depressed if only one set of speakers has been connected to either A or B speaker terminals.

So with that in mind, I get no sound if both are depressed with one speaker on A and one on B or two on A and one on B, I haven't tried it with all 4, but both my Hitachi and my parents circa mid 80's Pioneer as long as there's a speaker on the channel sound comes out. Is this Pioneer different in that it needs a pair of speakers on a channel to play? When I hook one speaker on A and one on B then I can get sound from A or from B but not both at the same time, still. Do I even have a problem or just a weird picky receiver?

I have some soldering experience, I have some electronics experience, but it's pretty small and limited to repairing car electrical issues mostly. If I have to break the A/B selection so A and B are always on all the time then that's fine with me, I just don't know where to start with this.

Thanks for your time, if this goes somewhere else please point me where so I can ask a moderator to move it. I know my stuff is junk compared to what many here are working with, but it's what I have.

 

[Moderation Team]

Moved to Solid State.

 

[rayma]

Hi, I've managed to acquire a few old but not old enough to be valuable or high end enough to be well documented receivers over the few short years on this earth.

I have a Hitachi SR-603 and a SR-304 with some scratchy pots and flaky switches that I'm going to try some Caig De-oxit pot and fader cleaner/lube and report back on. I'm sure they'll be fine and everything else works except some burned out back light bulbs. I love my Hitachi's, they sound great to my tin ears.

What I came here for actual help with is a Pioneer SX-2900. It has the usual 4 speakers spread across left and right channels with A and B channels as well for front and rear or whatever you wish. My problem is that ONLY A or ONLY B work, never both at the same time. I've sprayed some De-oxit into the switches and that fixed their flaky/scratchy problem (had to play with them to get them to work) but not the problem with only A or only B working. I'd like to be able to use more than 2 speakers with it, so I need some help trying to diagnose and then if I can repair this. I've read the owners manual and it states:

So with that in mind, I get no sound if both are depressed with one speaker on A and one on B or two on A and one on B, I haven't tried it with all 4, but both my Hitachi and my parents circa mid 80's Pioneer as long as there's a speaker on the channel sound comes out. Is this Pioneer different in that it needs a pair of speakers on a channel to play? When I hook one speaker on A and one on B then I can get sound from A or from B but not both at the same time, still. Do I even have a problem or just a weird picky receiver?

I have some soldering experience, I have some electronics experience, but it's pretty small and limited to repairing car electrical issues mostly. If I have to break the A/B selection so A and B are always on all the time then that's fine with me, I just don't know where to start with this.

Thanks for your time, if this goes somewhere else please point me where so I can ask a moderator to move it. I know my stuff is junk compared to what many here are working with, but it's what I have.

Maybe when both buttons are pressed, the speakers are connected in series.