CurtPalme.com Home Theater Forum

[trebortaergeht]

Bought a used 808 back in December as a christmas gift for me. It was working fine until today, I moved it slightly to plug in an hdmi cable and lost all sound output. The amp is not in protect mode, but the output relays are not closing, not getting any output on any pre-outs which leaves me to believe there is a fault in either the input or output boards. Everything else works fine, video in and out and the front panel.

I have the service manual, but I don't want to make the problem worse. Anyone know where I might get the input and output boards? If I send it for repairs, how much would it be for out of warranty service from onkyo, or does anyone have experience with an affordable 3rd party. I don't have very much money right now.

Thanks for any help.

[Boilermaker]

Does it work if you use an analog input?

[trebortaergeht]

doesn't work with any of the analog or digital inputs. It does know the format of the incoming digital signals, so the processing section still works.

[macgyver655]

The relays are for the speaker outs, not the preamp outs. Which are you using?

[trebortaergeht]

Ive tried both the pre-outs and speaker terminals, no output from either. Ive been studying the schematics, I'm going to pull my scope out of storage and check the protect and muting circiuts.

[macgyver655]

Some AVRs have a setting in the menu that when you select sound through the HDMI it turns off the internal amp.. Not sure if it does it for all inputs when selected or not. May want to check the user manual just to be sure.

Also is there a speaker on/off button?

[trebortaergeht]

already performed a factory reset and checked all settings. There is noswitch to turn the speakers off.

I'm thinking its either a fault in the preamp section, because the speaker relays do not engage with no signal, or in the protection circuit, because it also mutes the pre-outs and is what controls the speaker relays.

[macgyver655]

So where are you at with this?

[trebortaergeht]

haven't had much time to look at it. I was able to get some audio out through the headphone jack by hooking a signal up to the input of the amp section, but something strange happens. normally when you plug headphones in, the receiver goes into 2ch mode and opens all output relays to disconnect the speakers, now it closes the Right and left channel relay.

[macgyver655]

I would be looking for +22v on board U0031 (BATRM-0451), connector JL6604A, using pin 7 for ground and pin 6 for +22v.

If you have your +22v then on the same board locate JL9925A. Use pin 2 for gnd and check pin 1 for +15v and pin 3 for -15v.

This will get you started on which direction to go in.

[trebortaergeht]

not getting any voltage at those locations, however after looking around the board, i did test R9302 and R9303 as open and the voltage to the board passes through these. This is definitely the problem area as this board supply's power to both the pre-amp and relay circuits. Hopefully it is just the resistors but it could be the bridge rectifier or regulator that come right after. Should I replace the resistors and test it out or check the rest of the components on the board first?

EDIT:
That fixed it, checked the other components and didn't find any faults so i replaced the resistors, works fine. Now I need to reassemble it with out damaging it.

[macgyver655]