Originally Posted by TJMotter
Yup, thats exactly what happened to my NR807. I was able to fix myself by installing a new DSP chip. You should try Onkyo first to see if they will fix it for free for you. If not, ping me. When I bought the DSP for mine (didn't check with Onkyo at all but should have), the vendor had a minimum order quantity so I ended up with 11 extra parts.
Two things you can use to check:
1) with the system turned on, hold the "Display" key while you press the "Standby (On)" button. Within 5 seconds. press the - or the + tone button. This will bring up the firmware revision for the main CPU so next, press - or + again and keep pressing until you see "DSP-1". I will bet that instead of numbers you will find that they are all "??????????". If so, the DSP chip isn't booting and is the source of your problem. This was the EXACT reason for the Onkyo warranty extension.
2) with the system turned on, press "Setup" then scroll to "Hardware Settings". If the system is connected to your TV you will likely find that the "Network" and "Firmware Update" options are greyed out. I not, you will find that they don't show up when you scroll. The reason for this is that the DSP is also responsible for managing the Network and USB controls and since these are the only two options that Onkyo provides for accessing firmware updates, this also indicates that the DSP subsystem isn't working.
I have Onkyo TX-SR875 which is suffering from Popping/Crackling sound from front left and surround right channel, then both channel stops, now it is fall in "No Sound Issue". Earlier I check its firmware version it looks ok, but after having popping sound issue I try to firmware upgrade but It stucks in "Updating.....". Then it shows "?????????" when checking the firmware version. After resetting AVR firmware looks ok no more "?????". But still it has popping/crackling or no sound. Now I have some doubt please can u clear it?
1. Is it fault of HDMI Board?
2. If HDMI Board has DSP Chip and all then why separate DSP Board provided in ONKYO AVR? Where is DSP Chip (Problematic Chip) located in Onkyo TX-SR875? Is it possible to replace that bad chip with local expert service technician?
3. I also thought there was issue of DSP Chip and I bought DSP Board but still no sound from AVR, Video works very well why?
4. Onkyo starts a service camp for AVR which are having "No Sound Issue" but is this facility available for second customer? I mean to say If I am a second owner of Onkyo AVR then would I get free service facility?
5. Onkyo TX-SR875 works if HDMI Board removed?