Protection mode weirdness with Sony (1 Viewer)

[BrianKM]

I just picked up an older Sony STR-AV570 receiver and it's exhibiting some rather odd behavior. I'll turn it on and get a flashing red 'P' and none of the buttons will work, even though I'm not inputting a signal. Turning it off and on a few times will sometimes pull it out of protection mode, and it will work fine for eight hours straight. I turn it off, go to bed, and when I wake up the next morning, it's making this clicking noise near the amps that sounds like a breaker trying to reset itself. If I turn the receiver on at that point, it's already in protection mode.

Any idea what's causing this behavior?
Is it something I can fix myself?
Anything I can do, short of buying a new receiver?

Thanks in advance.

 

[Marty Neudel]

Brian,

you may want to run through this. Firt unplug the amp and all inputs and outputs from it. Let it sit for a few hours to reset itself. Then plug it in, (still with nothing except the power cord connected) turn it on, and let it run for 8 hrs. Turn it off, and let it sit overnight. If the problem does not recur then your Sony MAY be ok.

Next, plug one speaker in, turn the unit on, and let it run for a while. Repeat this for each speaker until the fault recurrs or all speakers are connected and working properly. Finally, repeat the above procedure for each input.

The above should isolate the problem for you.

Marty

 

[Craig_Kg]

Either one or more of your speakers are shorting (leads or internally) or the receiver is shorting out internally (more likely with an intermittent fault). If you don't have circuit diagrams and don't want to take it in to a repair shop, you MIGHT be able to fix it by taking the cover off and spraying the circuit boards with contact cleaner (edit - while the receiver is off and unplugged) but make sure the stuff you use is OK with plastic.

 

[Bryan Williams]

I am assuming that this reciever is a vintage 1991 or so. I worked for Sony at the time and many units in the X70 line had issues with bad cold solder joints. Among other things, this would cause the reciever to go into protect mode. Essentially, it is likely that the unit needs to be sent in to have solder joints redone. It is likely that there are service bulletins on this issue, but unfortunately the unit is out of warranty and the repair will likely exceed the value of the unit.

Regards