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Discussion Starter #1
Hi Friends,
Please help me so I dont have to take the unit out to the field and destroy it like the copier scene from the movie Office Space.

Anyway, my problem is the unit turns off before it fully boots up. I have researched till I was blue in the face and I am thinking it is probably going to need a trip to a service center which I really want to avoid. If there is a chance I can replace certain parts I am very able to do that. I've built several tube amps from scratch and fixed some solid state guitar amps.

The problem:
It started to shut off every once in awhile. I would turn it back on til it stayed on! But now it will not stay on. I disconnected all the speakers and still it turns off within 10 seconds. I measured all L/R posts to make sure they werent shorted together with no load/speaker. They all tested open. This unit was used in my garage for over a year. Would a little dust cause a problem? I've blown it out and there wasnt that much dust. As far as my speakers I'm using Fusion Alchemys which measured about 7.5ohms.

Thanks for any help!
 

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Hi Friends,
Please help me so I dont have to take the unit out to the field and destroy it like the copier scene from the movie Office Space.

Anyway, my problem is the unit turns off before it fully boots up. I have researched till I was blue in the face and I am thinking it is probably going to need a trip to a service center which I really want to avoid. If there is a chance I can replace certain parts I am very able to do that. I've built several tube amps from scratch and fixed some solid state guitar amps.

The problem:
It started to shut off every once in awhile. I would turn it back on til it stayed on! But now it will not stay on. I disconnected all the speakers and still it turns off within 10 seconds. I measured all L/R posts to make sure they werent shorted together with no load/speaker. They all tested open. This unit was used in my garage for over a year. Would a little dust cause a problem? I've blown it out and there wasnt that much dust. As far as my speakers I'm using Fusion Alchemys which measured about 7.5ohms.

Thanks for any help!
Open it and remove any dust that may be inside. In a garage, it's usually not only dust, but also moisture that gets in. And insects. Use a soft paint brush, but not while it's plugged into power and then, blow it out again.

That AVR should have no problem with your speakers- I used an AVR-990, AVR-991 and most recently, an AVR-2313CI for quite a while with my speakers and never had a problem. I built them about 5 years ago and never has an amplifier turned off.

Does the green ring flash red when it shuts off? If not, it's not dust- it's probably a regulator. If you know someone who does electronic service, it's not a difficult repair.
 

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Discussion Starter #5
And blow out the headphone jack too!
All cleaned out. It was very clean. I also blew out and deoxidized the headphone jack. Everytime I unplug the unit it takes up to a minute to shut off and under 10 secs every time after. And to reiterate I have nothing connected except the power cord.

So the cleaning did not work. Is it a power supply problem?
 

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Discussion Starter #6
Well youtube had a good lead for me to check. Highfigh spoke of it also. The +/- 15v rails are probably off due to the regulators which regulate them at + or - 15v are no good. Problem seems to be getting to the regulators. It is so tight in there.
 

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Discussion Starter #7
Need Schematic

Does anyone have a schematic or know about the topology of the Denon AVR-891? I am looking for the voltage regulators for the +/-15v. Every youtube video looks nothing like my receiver. My receiver has just one huge heat sink the length of the chassis behind the front panel. I figured they were the output chips. I also found some +/-5v regulators screwed to the bottom of the chassis.
 
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