Denon AVR-E300 in DC Protect Mode

[Ponchojack]

I've started troubleshooting this issue. I've cleared the code and it resets the error. Trying to figure out an approach. Looking for DC voltage in the output would seem the right move. First, determining which channel Front or Surround. Secondly, where to test? I would usually test the pins on the output relays, but they are on the bottom of the main board. Any idea the best place way to check the output?

I know you can disarm the auto shutdown by removing the harness BM502 between the Main and digital board. I've already inspected the board, tested main caps, and diode tested the power transistors.

Any good tech advice on approaching this DC protect problem would be appreciated. The troubleshooter in the Service Manual doesn't get you too far.

Poncho

[Ponchojack]

Re: Denon AVR-E300 in DC Protect Mode

Ok, maybe this will work. I can see the main board and schematic show pins for setting measuring the MV to bias each channel. Pin 2 is connected to the output for the last stage of each channel (image attached). I'm assuming you measure for DC voltage between this pin and chassis ground?

[R_J]

Re: Denon AVR-E300 in DC Protect Mode

Yes, check the voltage on pin2 of the plug, it should be close to 0v. You wil likely need to monitor the voltage when you first turn the amp on. If the amp goes into protection, the voltage will likely be 0 anyway due to shutdown.

[Ponchojack]

Re: Denon AVR-E300 in DC Protect Mode

Looks like one channel has a blown base resistor. What else usually goes? Nothing obvious yet, I'll have to dig deeper.

[R_J]

Re: Denon AVR-E300 in DC Protect Mode

Looks like one channel has a blown base resistor. What else usually goes? Nothing obvious yet, I'll have to dig deeper.

The transistor that is connected to it at a minimum,