My pioneer sx 203 stopped working. It no longer powers up. It was playing fine then I turned the volume up from 3 to 5 and it totally shut down. Doesn't work at all now.

I had a receiver that would shut off when I had the volume too loud. It was caused because the speakers were using too much juice. Does it work with less speakers or at low low volumes? Then this may be the case.

I solved it by getting a different receiver.

if it has nothing to do with volume then check your manual and settings for a auto standby feature that may be just putting the receiver to standby after a set time.

Mine is having this problem now.

Tried re-inserting the speaker wires.
Tried resetting before it shuts off.
Tried disassembling but solder joins are still nice.

It still shuts off soon after power up. Time to spend money? :(

Is the unidentified TV a sound source from the SX-315's perspective? Is it's audio output enabled whene the TV volume is down? Would the Cable Box be a BETTER source?

Your only recourse at this time is to check with local servicers that may have one around in their old stock. Or check Ebay for a parts machine that you can salvage one from. I believe that the volume control from an SX-850 will be the same, so you can search for one of those as well.

Good luck.

Dan

Are you sure it's not the TV telling you that it's muted? I went down the tubes on that one myself.

The receiver's Mute can be defeated by just rotating the volume knob upward. Ditto with TV's.

Power source harmonics. Or its power supply regulation. Check also if input line is touching something.

The unit is overheating, or at least thinks it is overheating.

Blow the dust out of the thing and see if that helps. If not, you have a thermistor that is bad or is going bad. Probably the thermistor nearest/on the audio amp transistor's heatsink.

???

1. Is the head unit powering the speakers directly or through an amp?
2. What ohm load (4,8,) per channel and how many speakers?
3. Does it do it with the bass set all the way down?

If you have access to a voltmeter see what the voltage is on the yellow and black wires when it is diming. It should be stable ~ 13.5v with car on. if its < 10v when dimming either there is:

1. Shorted speaker lead.
2. Bad ground to radio.
3. loose power feed to radio.
4. Ohm load below 4 ohms, causing the eccess current draw.

That is a common problem with this radio, for it can not go to loud without going down in volume or shutting down.

a little bit foolish thing: see if you have both the speaker channels (A and B) down. if you have both down it doesn't work - didn't for me.. and obviously make sure you have the right letter down - same outpout as your boxes