Denon Speaker Crackling problem

[sommert]

All –


I have Denon AVR 4306. It has a intermittent problem with nasty crackling coming through all the speakers. Sometimes it will go days without happening and sometimes multiple times a day. It happens when watching a DVD or HD Cable.. I tried eliminating HMDI and that wasn’t it. Anything I can check or replace myself or does it have to go for repair? I happen to catch a recording of it on my blackberry tonight while watching a movie on cable.

Here is the recording. I didn't touch anything while recording this. Notice how it goes right back to nice audio like nothing every happened. The sound comes through all speakers. It also doesn't matter if its holt cold, etc. No pattern whatsoever. Its like the wind.. comes and goes

Pretty nasty huh?

http://www.xglobal.net/denon.mp3


Thanks for any advice.

 

[TLS Guy]

All –


I have Denon AVR 4306. It has a intermittent problem with nasty crackling coming through all the speakers. Sometimes it will go days without happening and sometimes multiple times a day. It happens when watching a DVD or HD Cable.. I tried eliminating HMDI and that wasn’t it. Anything I can check or replace myself or does it have to go for repair? I happen to catch a recording of it on my blackberry tonight while watching a movie on cable.

Here is the recording. I didn't touch anything while recording this. Notice how it goes right back to nice audio like nothing every happened. The sound comes through all speakers. It also doesn't matter if its holt cold, etc. No pattern whatsoever. Its like the wind.. comes and goes

Pretty nasty huh?

http://www.xglobal.net/denon.mp3


Thanks for any advice.

That is clearly a fault in the digital domain not analog. Since it occurs with different types of inputs, it is unlikely the signal is getting corrupted on its way to the DAC.

I fear the DAC of your unit is going down. This is part of the very heart of the "engine room" of your receiver so to speak.

I hope your unit is still in warranty, as this is one of those situations were repair costs are likely to be very high.

 

[Patrukas777]

I had the same problem with my Denon 1508ci AVR. It started out crackling through the speakers in the begining... after a month or two of this, it started crackling and shut off. My 1508 was my first receiver. I sent it to Denon two weeks ago. I will let you know what they replace. I'm supposed to receive it on the 25th of this month.

 

[TLS Guy]

I had the same problem with my Denon 1508ci AVR. It started out crackling through the speakers in the begining... after a month or two of this, it started crackling and shut off. My 1508 was my first receiver. I sent it to Denon two weeks ago. I will let you know what they replace. I'm supposed to receive it on the 25th of this month.

You receiver is a current model, so I assume it is still under warranty. The OP's is not a current model and fear it is likely out of warranty, which my present him with a dilemma of whether to fix or not. I see it is HDMI version 1.1

 

[sommert]

My Denon is out of warranty. How expensive is expensive to repair? I would have it fixed if i knew I would get years out of it. I bought Denon because I thought it was top notch stuff. I am almost 40 and had a lot of stereo stuff in my life. Denon is the only one that has failed me. I am pretty good with electronics and soldering if I can get the part myself and put it in. Not sure what to buy though or who to buy it from.

 

[TLS Guy]

My Denon is out of warranty. How expensive is expensive to repair? I would have it fixed if i knew I would get years out of it. I bought Denon because I thought it was top notch stuff. I am almost 40 and had a lot of stereo stuff in my life. Denon is the only one that has failed me. I am pretty good with electronics and soldering if I can get the part myself and put it in. Not sure what to buy though or who to buy it from.

I'm over 60 and its not like the good old days. Digital circuits you can't trouble shoot with a generator, multimeter and scope.

The next problem is that components are generally surface mount placed by robot. It is not at all like the old days with through and through components.

I do believe that some receivers have some degree of self diagnostic ability for well equipped shops. You are generally committed to replacing a whole board rather then a component.

Unfortunately you may have to have the whole processing board replaced.

See if you can find a shop that will give you an estimate. However I personally feel a shop can, and should charge for diagnosing faults. This may be around $70 or more for a start.

The next issue is that this fault likely has nothing to do with it being a Denon.

Denon don't build the chip sets.

The real problem is way too many features.

Receiver manufacturers are loading up with far too many features, as that seems to get sales. We are now at the point where I'm certain this is going to reap a grim harvest.

One of my sons is a research engineer and designs powerful chips. He is very good at electromagnetic simulation.

The problem as he explains it to me, is that as you increase processing power, then you build in shorter life and unreliability.

The reason is that you can only make the chip more powerful, by making the semiconductor layers and the devices in the chips smaller and smaller. If you make the chips bigger they don't work, because of the speed of conduction within the chips. His electromagnetic simulations predict all this.

Now when you make the semiconductor material thinner, you have greater risk of a spark starting to punch wholes in the semiconductor material. When those wholes start to conduct, then you get the problems you are experiencing. Eventually the electrodes weld and you have a dead short, and shut downs from the protection systems.

Really putting these types of circuits in the same case as a big power supply,
and seven powerful amps, and at the same time add power and features to the processing boards, is asinine.

Unfortunately the industry is geared to receivers. I have never used one and never will.

I think that we should go to preamp processors, and put the power amps in the speakers where they belong. Active crossovers and amps for each pass band in the speakers, has the potential to increase quality and reliability.

 

[audiofox]

One of my two Denon 3806 receivers had a problem where the rear channel amplifiers would not output any signals to the speakers. The Denon repair center quoted me a repair cost of $300, which included replacement of the CPU board-the clerk claimed it was the actual CPU, but I looked up the part number online and discovered that it was the entire board, which sells for around $190. This board is the largest board in the unit and is at the bottom of the chassis, so if your receiver problem is on the same board, it may not be as bad as you fear. The 4306 is a very nice receiver, so you may want to go for repair instead of replacement -I was looking for an excuse to replace my 3806 (don't tell the S.O!), so I sold it to a sparky friend of mine for an extremely attractive price and got a 3808 to replace it.

 

[sommert]

Thanks. What was the turnaround time?

One of my two Denon 3806 receivers had a problem where the rear channel amplifiers would not output any signals to the speakers. The Denon repair center quoted me a repair cost of $300, which included replacement of the CPU board-the clerk claimed it was the actual CPU, but I looked up the part number online and discovered that it was the entire board, which sells for around $190. This board is the largest board in the unit and is at the bottom of the chassis, so if your receiver problem is on the same board, it may not be as bad as you fear. The 4306 is a very nice receiver, so you may want to go for repair instead of replacement -I was looking for an excuse to replace my 3806 (don't tell the S.O!), so I sold it to a sparky friend of mine for an extremely attractive price and got a 3808 to replace it.

 

[TLS Guy]

One of my two Denon 3806 receivers had a problem where the rear channel amplifiers would not output any signals to the speakers. The Denon repair center quoted me a repair cost of $300, which included replacement of the CPU board-the clerk claimed it was the actual CPU, but I looked up the part number online and discovered that it was the entire board, which sells for around $190. This board is the largest board in the unit and is at the bottom of the chassis, so if your receiver problem is on the same board, it may not be as bad as you fear. The 4306 is a very nice receiver, so you may want to go for repair instead of replacement -I was looking for an excuse to replace my 3806 (don't tell the S.O!), so I sold it to a sparky friend of mine for an extremely attractive price and got a 3808 to replace it.

The 4306 seems to command about a grand more than the 3806. I had a look round the net for a CPU board for a 4306 and came up empty. I fear the board for the 4306 will be much higher priced, assuming his receiver even needs a CPU board, which is a significant assumption. However, the 4306 is an expensive receiver, so putting up to $600 into repair might be justified, if that is what it will take.

If you go the repair route, then when you get it back running it via a smart UPS with response time of under 2 ms would help reduce the chance of failure. Using external amplification for at least the three front channels would reduce heat and also make failure less likely.

With all these feature laden receivers appearing I fear an epidemic of CPU failures is about to become a pandemic.

 

[davidtwotrees]

.....
Using external amplification for at least the three front channels would reduce heat and also make failure less likely.......
With all these feature laden receivers appearing I fear an epidemic of CPU failures is about to become a pandemic.

Useful info indeed. So. I have recently purchased a midlevel receiver. Onkyo SR706. I did have a pretty beefy Parasound HCA2003 amp running the front 3 channels.........but sold it for a myriad of reasons, not least of which is that I need the cash..............so, I still own a small Parasound HCA750A. Are you saying that running that amp which has about the same output as the receiver, will help keep the heat down in my Onkyo and reduce the chance of problems due to heat buildup? Thanx in advance, Dr. TLS.
ps. wife2b is ok with the canton's!

 

[TLS Guy]

Useful info indeed. So. I have recently purchased a midlevel receiver. Onkyo SR706. I did have a pretty beefy Parasound HCA2003 amp running the front 3 channels.........but sold it for a myriad of reasons, not least of which is that I need the cash..............so, I still own a small Parasound HCA750A. Are you saying that running that amp which has about the same output as the receiver, will help keep the heat down in my Onkyo and reduce the chance of problems due to heat buildup? Thanx in advance, Dr. TLS.
ps. wife2b is ok with the canton's!

Absolutely yes! As I have pointed out before, every solid state device has a temperature use longevity curve. Keeping the device operating below 60 degrees Celsius provides optimal life. However it is a log curve, so the slope is gentle at first and then takes off going straight line upwards.

So cool running is extremely important for high powered CPU chips which are the most fragile. The whole concept of the AV receiver is becoming increasingly flawed every year as features are added.

This is especially important now the technology is becoming mature. Already going from DVD to Blue Ray had been a hard sell. Going above Blue Ray with its loss less audio, I think would be an impossible climb for many years. Therefore longevity of equipment is big and timely issue. So buying for the long term is now very reasonable. If you have a good screen AV processor, good speakers and amp, I think it should not be a stretch to think in terms of at least a 20 year lifespan.

There is no way to responsibly recycle electronic equipment, and its very toxic. That is a dirty little secret. Even the EPA have been discovered discarding old computers in Ghana and contributing to the poisoning of children. So this is another reason to try and extend the life cycle of electronic equipment. And that includes automobiles that will have more electronics than your home theater.

 

[MatthewB.]

I have found it's best to buy a small computer fan and place it on the back right side of the Onkyo to keep it very cool. This is where the video processing chips are stacked generating far more heat than the amps themselves, but agree a seperate amp will help to relieve the reciever of it's working hard to drive the speakers and helping to keep it cool.

Sorry to hear about your Denon,, they make very good products (I have a 4802 and a 3808) and love em, but agree that with so many features and so many things that a reciever has to do, that any small snafu could crash the reciever, In my experience it has been faulty cold solder joints.

 

[TLS Guy]

I have found it's best to buy a small computer fan and place it on the back right side of the Onkyo to keep it very cool. This is where the video processing chips are stacked generating far more heat than the amps themselves, but agree a seperate amp will help to relieve the reciever of it's working hard to drive the speakers and helping to keep it cool.

Sorry to hear about your Denon,, they make very good products (I have a 4802 and a 3808) and love em, but agree that with so many features and so many things that a reciever has to do, that any small snafu could crash the reciever, In my experience it has been faulty cold solder joints.

The solder is another issue, since RoHS regs have made them take lead out of solder. IMO you can't make a decent solder joint without leaded solder. The solder does not flow, and one to two years it sprouts whiskers and shorts the boards.

Buy as much vintage gear as it practical to use!

 

[MatthewB.]

I'm in total agreement TLS Guy, if it werent for the new lossless audio formats and my need fror HDMI, I would still be using my older gear.

 

[audiofox]

The 4306 seems to command about a grand more than the 3806. I had a look round the net for a CPU board for a 4306 and came up empty. I fear the board for the 4306 will be much higher priced, assuming his receiver even needs a CPU board, which is a significant assumption. However, the 4306 is an expensive receiver, so putting up to $600 into repair might be justified, if that is what it will take.

If you go the repair route, then when you get it back running it via a smart UPS with response time of under 2 ms would help reduce the chance of failure. Using external amplification for at least the three front channels would reduce heat and also make failure less likely.

With all these feature laden receivers appearing I fear an epidemic of CPU failures is about to become a pandemic.

The failure was not the CPU itself, but the relay drivers that reside on the CPU. Since they are surface mounted (ie, not in IC sockets), the repair center chose to quote a cost for the entire board, even though the parts are relatively inexpensive. Turnaround time was quoted at a week, and the board is available online from multiple vendors.

We found a service manual online, which has the following part number for the 3806 CPU board: 1U-3700. If you want a service manual for your 4306, you can get it here for $7 (downloadable pdf):

http://srvman.com/dmuou1vr4306rmrvicm28u58l-p-585.html

Here is one vendor that sells the board, whose cost is similar to that quoted by Gold Crown Electronics, the repair center I use (their price was $190):

http://www.encompassparts.com/products/?1U-3700

I have no idea if the 4306 CPU board is similar in cost, but since there are only a few differences between the two models, mu guess is that it is close.

BTW, my assumption about the CPU board was to bound the cost, not diagnose the problem-this board appears to be the most expensive one in the unit, so if the 4306 costs are similar, the total cost should be as well.