Onkyo AV Receiver TX-SR503 While sleeping with earphones connected, the receiver shut down and the standby light blinked. I unplugged the power cord, reconnected power and the receiver shut down immediately after turning power on.

Try resetting the AV receiver To reset the AV receiver to its factory defaults, turn it on and, while holding down VCR/DVR, press 8 ON/STANDBY. "Clear" will appear on the display and the AV receiver will enter Standby mode.

It is possible that the protection circuitry has been activated. Remove the power cord from the wall.. Disconnect all speaker cables and input sources, and then leave the AV receiver with its power cord disconnected for 1 hour. After that, reconnect only the power cord and set the volume to maximum. If the AV receiver stays on, set then the volume to minimum, disconnect the power cord, and reconnect your speakers and input sources. If the AV receiver turns off when you set the volume to maximum, disconnect the power cord, and contact your dealer.

If the standby light is lit it and the unit will not boot it is most likely that the protection circuit has been activated. If there is no standby light then check the fuses. These units check that the power supplies are operating near specification. If a capacitor or resistor in the circuit, or a broken solder connection the unit will shut down. Because of the temperature the thermal cycling around the power supplies a broken solder joint can occur. This will make for an intermittent operation.

Hope this helps.
Failed resistor or capacitor

The amp protection circuit has been activated. Remove the power cord from the wall outlet immediately. Disconnect all speaker cables and input sources, and leave the AV receiver with its power cord disconnected for 1 hour. After that, reconnect the power cord and reconnect an input and a pair of speaker wires onto the unit. If the receiver still does not turn on than you will have to bring it in for service. Turn up the volume and if the receiver doesn't shut down, power off the receiver and add another pair of speakers. Power up the unit again and turn up the volume. If it doesn't shut down, power off the unit again. Now connect all your input sources and turn on your receiver. If the unit shuts down again, your unit will need to be further serviced at an authorized Onkyo service center.

The amp protection circuit has been activated. Remove the power cord from the wall outlet immediately. Disconnect all speaker cables and input sources, and leave the AV receiver with its power cord disconnected for 1 hour. After that, reconnect the power cord and reconnect an input and a pair of speaker wires onto the unit. If the receiver still does not turn on than you will have to bring it in for service. Turn up the volume and if the receiver doesn't shut down, power off the receiver and add another pair of speakers. Power up the unit again and turn up the volume. If it doesn't shut down, power off the unit again. Now connect all your input sources and turn on your receiver. If the unit shuts down again, your unit will need to be further serviced at an authorized Onkyo service center.

i try to repair but still c/n on >.< need to on loan board try repair

Any digital source must have its input assigned (page 31 of the manual). The DVD player has a role in this, too. Try another cable or input.

If you have the manual, crack it open and follow it's advice for your symptom. Then look at every indicator and control to evaluate how it fits into your desired listening experience. UNDERSTAND the receiver or you will forever have issues with losing the 'sound' because a seldom-used control got touched by mistake.

Register and download the manual for free at retrevo.com

http://www.retrevo.com/support/Onkyo-TX-SR503-Receivers-manual/id/365ag216/t/2/

If you still feel a reset is necessary look at page 57 or search the document for "factory defaults".

To reset the AV receiver to its factory defaults, turn it on and, while holding down the [VIDEO 1] button,

press the [STANDBY/ON] button. "Clear" will appear on the display and the AV receiver will enter
Standby mode.

Hi,

To reset the Onkyo TX NR3007 AV receiver to its factory defaults, turn it on and, while holding down the [VCR/DVR] button, press the [ON/STANDBY] button. “Clear” will appear on the display and the AV receiver will enter Standby mode.
Thanks for using Fixya.
Good Luck and have a nice day.

Exactly an hour? Is the Sleep Timer enabled?

Hi...1st off ...make sure all the speakers are connected at both ends.
2nd..buy a new cat..one that doesnt drool.
If it's still stays in Stdby after checking speakers, It might have blown an internal fuse cause thats where those darn stereo people put them now.

Disconnect everything from the amp except the power cord, then power on the amp. If the receiver still shuts down, your problem is inside the case and unless you can perform electronic repair yourself you will probably need to take it in for service. If it does not shut down with nothing connected, power it off, connect one speaker or component and power on again. Repeat the process until the amp shuts down and you may have found the bad speaker or other component.

i have the same problem with a onkyo tx ds494