Pioneer SX-737 Clicking Off, Bad Relay?

My SX-737 has clicked off for a while, but it usually just snapped right back on a couple seconds later. Over time it started taking longer and longer, and now, it's pretty much just constantly in protection mode whenever it's on. I was looking around online and came across this thread with similar issues. (http://www.audiokarma.org/forums/showthread.php?t=483797).

Using my multimeter, I tested the pin values MarkTheFixer posted, and almost every one of them was totally off. Using pin 4 as a ground, the rest of the values are as follows while it was in protection mode; Pin1: 5.5v, Pin2: 5.5v, Pin3: 5.2v, Pin9: -40.8v, Pin10: -13.2v, Pin11: 0v, and Pin12: -41v.

Obviously these are severely incorrect, and I know very little about the inside of this stuff. Any thoughts or ideas on what's wrong and what I should do next? I assumed I'd just have to replace some stuff, but looking in the case, I don't see any blown caps or burnt transistors, but it seems like there's more components underneath that I can't see that could possibly be bad.

Any help is appreciated and I can answer any questions or take pictures or do whatever tests people recommend. Thanks in advance.

are those voltages for the correct board ?protection board AWM-025
having trouble following those readings ...
are the lights all working on the front panel ?

have copied marks instructions for easy reference ................................................................................................................................................................
remember to INSULATE all but the TINIEST portion of the tip of your red dmm probe for when you (we ALL slip) slip, to avoid further damage. Plain old scotch tape works fine.

Then on the protection board AWM-025 measure and watch these pins :
pin 1 0.000v DC this is an amplifier channel output (to the speakers, before the relay cuts it off) DC offset when volume is turned to zero
pin 2 -13.0v DC a power supply voltage
pin 3 0.000v DC this is the OTHER amplifier channel output (to the speakers, before the relay cuts it off)
pin 4 a convenient ground point for the black lead of your dmm, although a bare metal chassis ground IS preferred
pin 9 this is the "bottom" of the relay coil, and is what allows current to flow to pull IN the relay, 35v when relay isn't activated, 9 volts or so when relay is pulled in
pins 10 and 11 +35v DC power for the whole shebang
pin 12 7.5v AC this is a "tap" on the lighting circuit and signals that the receiver is turned on (or off). a blown lighting fuse will shut down the sound!!

There is a REASON why I say "bare metal chassis ground". It is because if the supposed ground pin ISN'T a ground 0r the wire broke, ALL the readings are weird.

And as Pete has alluded to, we identify WHICH board explicitly by the zzz-999 type number so there is no confusion.

Now, that said, I have found NO pictures of the bottom chassis of a sx-737, to infer what guideposts you used to identify pin 4 and it's brothers. And your comment

but it seems like there's more components underneath

Click to expand...

leaves me to believe that you haven't measured the protection board, which is in the UNDERSIDE of the chassis.

PLEASE PLEASE PLEASE, LOOK at the board you measured, describe it to us, and try hard to find that ZZZ-999 board identifier.
The candidates on top are:
AWR-057 power supply models KCU, F
AWR-058 power supply model GN
AWE-043 tuner
and recessed a bit in the hole: AWH-033 Power amplifier


HAVE you downloaded the service manual? Please do so, and READ or at least LOOK at EACH page, so that things can start to fit together in your mind.

I WILL say that the SX-737 HAS the dreaded 2SC1451 transistors, as well as the 2sa726 transistors in the power amplifier, all which will fail and will take the amp with them, so they must be preemptively replaced...