Need help with my Denon receiver - PROTECT

C

cali1115

Audiophyte
I was rewiring speakers for my home theater yesterday. I was testing the center channel, when all of a sudden my AVR-900 started buzzing, flashed "protect", and then shut off. The display turned off completely. I later found out that a connection to my center channel had accidentally disconnected.

I unhooked all components and speakers and unplugged the receiver, thinking that it was a short in a speaker wire. However, even with no components and speakers connected, the receiver still will not leave standby mode and there is nothing on the display. The standby light alternates between steady and flashing when I hit the power button.

Some websites have mentioned that I may need to reset to factory settings. Does anyone know how to do that for the AVR-900 (or the Denon reset procedure) and/or if there are some other steps you recommend that I take to fix this problem?

Thanks!

Brian
 
crashguy

crashguy

Audioholic
I can check the manual I have for the AVR-1500 I own. There is a procedure to "initialize the microprocessor" as Denon calls it. I would think that my 1500 would be similar to your 900. I am at work right now, but can check and repost when I get home.

You may also want to contact Denon via email as well. They may be able to help you, although it would likely take a few days to get a response.

You may be in the market for a new unit....
 
R

rschleicher

Audioholic
You may want to try un-plugging the power cord, and leaving it unplugged for some period of time. Some receivers will restore to factory defaults if left unplugged (this would be described in the manual, as well as the length of time you need ti leave it unplugged). This allows for total discharge of small power-back-up circuits that are designed to maintain the memory of various receiver settings, during normal short power interruptions. At least it is a cheap experiment worth trying.

My old Yamaha pro-logic-only receiver gave up the ghost with similar symptoms - it would automatically shut off within a couple of seconds of being powered up, even with no speakers connected at all. It was either some sort of internal short of the amplifier output transistors, or possibly a failure of the protection circuitry itself. Since this gave me a good excuse to get a new 7.1 receiver, I wasn't too unhappy :)
 
bigbassdave

bigbassdave

Full Audioholic
I had the same problem with an Onkyo 702. At first I thought I shorted it out some how but later found that was not the case. What I suggest you do is this. Unhook all speaker wires. Then hook them up one at a time and try listening to something. If it plays then that particular wire is not the problem. Do this until all the speakers are hooked up. If any of your wire has a crack in the protective coating and is touching something that could cause your receiver to go into "Protect" mode. My problem ended up being that the wires in the back of my receiver were freid and touching one another. Good luck!
 
crashguy

crashguy

Audioholic
On my AVR 1500, it says to unplug the unit from the wall, hold down both video select and audio select at the same time, plug it back in. Keep holding both buttons for 2 secs, unit will reboot.
 
K

kronos

Audiophyte
Denon Receiver

I also have a Denon receiver that started buzzing last week; however, all of the buttons, display, etc. work, but I after turning off and on, I cannot get any sound from the receiver....would unplugging it for a while or the "Initialize The Microprocessor" help with this?? I took it back to Best Buy but they didn't want to attempt to trouble shoot it for me, just looking for some advise before shipping it to a repair center.

Thanks
 
M

markw

Audioholic Overlord
Can't hoit.

I also have a Denon receiver that started buzzing last week; however, all of the buttons, display, etc. work, but I after turning off and on, I cannot get any sound from the receiver....would unplugging it for a while or the "Initialize The Microprocessor" help with this?? I took it back to Best Buy but they didn't want to attempt to trouble shoot it for me, just looking for some advise before shipping it to a repair center.

Thanks
I doubt it but what's it cost to try it? I'm surprised you didn't already.
 
K

kronos

Audiophyte
I've tried about everything I could think of (or find in the manual) to reset it, but my troubleshooting guide doesn't give any resets. I have the AVR-487, but I will certainly try a few of these tips, can't screw it up any worse than it is now so definitely worth the shot.
 
njedpx3

njedpx3

Audioholic General
The reciever is about 13 years old; it couldbe a capacitor problem.

=========
You can try resetting

1) unplug unit
2) press and hold tuner and video select on front panel
3) plug in while holding buttons

Unit display should flash until you let go of buttons.

Unit stays on you should be ok/ goes back to red- service

=============

There are 3 types of protection that will commonly occur on Denon receivers which are designed to protect the unit from permanent damage.

1) Thermal Protect = When the unit overheats this will occur, usually if there is not enough air space above and around the unit. There cannot be anything directly on top of the unit and there must be at least 4 inches of airspace above the unit. If not hot this shouldn't be a problem.

2) Overload Protect = Most commonly occurs when a strand or more of copper speaker wire is not securely connected to the speaker terminal and is touching the chassis of the receiver. If the volume is turned higher than 85% this may also occur. If you need to turn the volume higher than this point to get the level you want, you need a more powerful amp. You said you disconnected the speakers, but also turn your volume all the way down. see if it powers on and if so then add one speaker at a time back.


3) DC Protect = When an amplifier fails this will occur. This will protect dc current from damaging the speakers. When this happens the unit will need to be serviced. This will be true if your power capicitor is shot/blown which can happen on older AVRs. This will probably mean a service call.


Denon is my brother.. to my Marantz. Worth getting fixed :cool:


Good Luck!

Forest Man.
 
Last edited by a moderator:
K

kronos

Audiophyte
13 years old?? They must have had this shelved for a while because I bought it less than 2 years ago. Thanks for the heads up though I will give this a shot tonight when I get home and I'll reply here tomorrow to give you some results.
 
njedpx3

njedpx3

Audioholic General
The Denon AVR-487 is a 2007 model, only two years old indeed.

Here's a review:
@ http://www.audioholics.com/reviews/htib/denon-dht-487dv-home-theater-in-a-box-review

* By turning your receiver OFF, then unplugging it from the wall outlet for about 30 seconds;
then replugging it, and turning it back ON;
it should reset itself, and becoming reoperative. Try it, and see.

** If to no avail, let us know, and we'll try to diagnostic your problem. :)
OP was asking about the Denon AVR-900
 
Lordoftherings

Lordoftherings

Banned
You are absolutely correct.

OP was asking about the Denon AVR-900
Sorry, my mistake. Your post was just below the fellow mentioning the Denon AVR-487.
From that my confusion...

I stand corrected.
Please, do accept my apology.

Regards,
Bob
 
AVRat

AVRat

Audioholic Ninja
Yeah, but the OP is 4 yrs. old!:p Gotta watch the post dates.
 
R

rohana mallawarachchi

Audiophyte
I had the same problem PROTECT with my Denon AVR-900. Checked all output transistors and found OK. Later found one 7812 regulator not receiving voltage to it. Found there is a small transistor like component
called a Circuit protection element ICP-N20 in open circuit. Same was bypassed and found unit working OK. Check all the major voltage points in the set to confirm that they are OK. Other vice the Microcontroller will issue protect signal. Most probably you have had a short circuit in the center speaker system. Check output transistors on same board for malfunction. Reset for microprocessor is press and hold tuner and video select on front panel when set is unplugged and plug it in to power. You will see all zeros appearing and changing display back to all zeros in panel. Good luck if You are still interested.
 
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