Onkyo TX-DS575

[frankusb]

I pulled Q3383 completely and there is no more popping from enabling/disabling the B speakers. My theory is that this is also the source of the changing input protection since it will mute during change and then pop from ground to -2V.

The only unexpected behavior (to me anyway) now is that the protect is always being asserted on power up from the surround/remote amp board.

I ordered the part and it will be here next week.

[frankusb]

Thank you redwire for your help. I got the part in the mail today and replaced it and everything is working perfectly. Now I have 9 extra RN1241s. Q3383 has been replaced and no more protect shut offs or popping from Speaker B.

[frankusb]

Heh, I thought I was out of the woods but the remote does not work. It's not the remote as it works with another receiver. Back to the schematic.

[frankusb]

Heh, I thought I was out of the woods but the remote does not work. It's not the remote as it works with another receiver. Back to the schematic.

The IR sensor was bad. Nothing on the signal line when receiving an IR signal. I swapped in another sensor from a scrap receiver and now it's working.

[frankusb]

Dang it, I'm still getting a protect on power up sometimes. FMUT is 2V on power up and goes to 0V after enabling the speaker relay. The base on the muting transistors is not changing so I suspect Q3185.

[frankusb]

Dang it, I'm still getting a protect on power up sometimes. FMUT is 2V on power up and goes to 0V after enabling the speaker relay. The base on the muting transistors is not changing so I suspect Q3185.

It seems it was a poor connection. I re-flowed from FMUT to the diode D3182, transistor Q3185, the jumper wires to the mute transistor inputs and all seems well with protect.

The bad news is the remote sensing has mostly stopped working.

[frankusb]

The bad news is the remote sensing has mostly stopped working.

That seems to have been a bad solder joint as well. The remote is working again.

If everything holds, the final repair tally was one muting resistor and one remote sensor.

[frankusb]

In usage, the settings don't last long without being in standby. I was thinking the super capacitor should be replaced. The schematic and parts lists seems to differ in capacity. it seems like the higher the farads the longer the settings will be retained. R7079 should limit the charge current?


The C7002 part number is for a 0.1F but the schematic shows 0.047F. I'm inclined to get the 0.1F. Is this the right part to use?

[redwire]

Yes, C7002 is an Elna super-cap DX-5R5L104 0.1F 5.5V and upsizing it is OK. The schematic shows it as 0.047F so they already did it.

[frankusb]

I put in a new super cap and the settings now save for much longer, lasted overnight.