It's possible to bypass the protective mode on any onkyo receiver here is how you do
Operation of Self—diagnostic
Self-diagnostic will start at the timing of next power on, after goes to the protect mode by Current detection or DC voltage detection.
Only On/Standby key could work in this mode. Also remote control does not work.
However, the CLEAR operation is enabled.
During Self-diagnostic, the power supply for amplifier circuit become low voltage state(SEC1-LOW), and the speaker relay will be turned off. Then, MPU will check each amplifier circuits internally by entering the test signal (20 kHz,-20 dBFS sine wave) to each channel from DSP.
MPU will judge the amplifier circuit is good or not from VOLH value.
The normal range of VOLH value is 0.04 V < VOLH < 0.20 V.
If VOLH value is in the out of this range, it will be judged as NG (No good).
No problem found
When protected by current detection, and no problem found, "CHECK SP WIRE“ will be displayed in this State, Only the On/Standby key is effective. And it do not anything for 3 minutes, unit goes into stand by automatically.
When protected by a DC voltage detection, and no problem found, unit goes into normal operation.
Problem found
When judged as there is a problem on any channel, the information of channel that has a problem will be displayed. In this State, Only the On/Standby key is effective. Also remote control does not work. if do not anything for 3 minutes, unit goes into standby automatically. This state will keep also after unit turn on/off, or AC unplugged.
The power supply for the amplifier becomes low voltage state and the speaker relay will be turned on.
Repair Process and How to Confirm
Confirmation of the protect cause
While NG channel is displayed, You can confirm the protect cause by following the step below
1. Press the Enter button
2. The protect cause are displayed for 5 seconds.
Please check the around of those amplifier circuit and repair it.
Clear of NG CH information
After repair, you can clear NG CH information by following the steps below.
1. Press the On!Standby key while pressing the Enter key.
2. Display as in the right figure appears.
3. Unit goes into Standby automatically after 5 seconds.
Self-diagnostic will start again at the timing of next power on.
By this, You can verify whether repair was properly or not.
If problem found after repair, please re-check the around of its circuit.
Cancel of Self-diagnostic
You can cancel this mode by clear operation (press Standby key while pressing CBL/SAT key)
After cancel this mode, receiver will be started as normal operation.