WTB: factory printed service manual for Denon AVR-3312Ci

[Bruce Toski]

I'm 68 years old, born in Miami Florida, Master ASE automotive technician, wannabe technician for electronics.

One of my speakers shorted out and now my receiver is in protection mode. I tried the reset, with no speakers attached, no change.
I disassembled the entire receiver cleaned everything, inspected, put it back together ... still the same. I'm getting a 3.7 volt surge on the ASODET trace which takes me back to a very small surface mount transistor on the back side of the HDMI PCB which appears to be part of the protection circuit.

Anyway I ordered this surface mount transistor and the surface mount capacitor next to it along with a $300 infrared solder desolder inspection station.

I well the PDF but, does anybody have the factory service manual in printed format, original, that they would sell me ?
I bought a service manual for the 3300 model, thinking it might be close, but that was a mistake and I have it for sale, $20, for anybody who has a 3300 model !

 

[TLS Guy]

I'm 68 years old, born in Miami Florida, Master ASE automotive technician, wannabe technician for electronics.

One of my speakers shorted out and now my receiver is in protection mode. I tried the reset, with no speakers attached, no change.
I disassembled the entire receiver cleaned everything, inspected, put it back together ... still the same. I'm getting a 3.7 volt surge on the ASODET trace which takes me back to a very small surface mount transistor on the back side of the HDMI PCB which appears to be part of the protection circuit.

Anyway I ordered this surface mount transistor and the surface mount capacitor next to it along with a $300 infrared solder desolder inspection station.

I well the PDF but, does anybody have the factory service manual in printed format, original, that they would sell me ?
I bought a service manual for the 3300 model, thinking it might be close, but that was a mistake and I have it for sale, $20, for anybody who has a 3300 model !

My hunch is that the protection circuit is fine. I think it is doing its job. A short like you describe generally takes down at least the power transistors in the amp that was exposed to the short. That creates a short circuit in one or both, usually both of the output transistors. This triggers the protection circuit to stop blowing up the power supply..

So my strong hunch is that the power transistors in that power amp need replacement and very likely the driver transistors and associated diodes.

Unless you are experienced and have good test equipment you are unlikely to repair this unit.

Service manuals are not usually issued these days and are considered proprietary. With surface mount components the chance of a successful home board repair is remote.

The other issue is that your receiver is 13 years old and therefore close to the end of its useful life. 14 years is considered a typical lifespan for a receiver. So, I am not sure the unit is worth any trouble or expense. Probably time to cut your losses and replace it.

 

[lovinthehd]

I'm 68 years old, born in Miami Florida, Master ASE automotive technician, wannabe technician for electronics.

One of my speakers shorted out and now my receiver is in protection mode. I tried the reset, with no speakers attached, no change.
I disassembled the entire receiver cleaned everything, inspected, put it back together ... still the same. I'm getting a 3.7 volt surge on the ASODET trace which takes me back to a very small surface mount transistor on the back side of the HDMI PCB which appears to be part of the protection circuit.

Anyway I ordered this surface mount transistor and the surface mount capacitor next to it along with a $300 infrared solder desolder inspection station.

I well the PDF but, does anybody have the factory service manual in printed format, original, that they would sell me ?
I bought a service manual for the 3300 model, thinking it might be close, but that was a mistake and I have it for sale, $20, for anybody who has a 3300 model !

Why not just print out the pdf?

 

[TLS Guy]

Why not just print out the pdf?

The pdf. he has is for the wrong receiver, so there is no point in printing it.

 

[lovinthehd]

The pdf. he has is for the wrong receiver, so there is no point in printing it.

He mentioned them separately and he's offering the 3300's for sale....but what exactly "I well the PDF but" means I'm not sure of otoh.

 

[lovinthehd]

I see you've quoted my reply but don't see anything from you....

 

[Bruce Toski]

Gents, I meant to say that I have the proper PDF now, but I am not able to go back in fix my textual error for some reason. I thought I stated the reason that I want a printed copy. The factory publications have nice size, 16 inch by 22 in, fold out schematics. Even if I go to the time and expense to drive to Kinko's to print those pages out properly, I doubt they will still be as nice of the factory publication. Initial tests with the Darlington output transistors, indicate that they are good but I have ordered another transistor tester to double check. The attached picture is of the surface mount transistor which is in the ASODET circuit. It is testing bad in circuit and it looks like it got hot, I don't know what is that red stuff ?

 

[Bruce Toski]

My hunch is that the protection circuit is fine. I think it is doing its job. A short like you describe generally takes down at least the power transistors in the amp that was exposed to the short. That creates a short circuit in one or both, usually both of the output transistors. This triggers the protection circuit to stop blowing up the power supply..

So my strong hunch is that the power transistors in that power amp need replacement and very likely the driver transistors and associated diodes.

Unless you are experienced and have good test equipment you are unlikely to repair this unit.

Service manuals are not usually issued these days and are considered proprietary. With surface mount components the chance of a successful home board repair is remote.

The other issue is that your receiver is 13 years old and therefore close to the end of its useful life. 14 years is considered a typical lifespan for a receiver. So, I am not sure the unit is worth any trouble or expense. Probably time to cut your losses and replace it.

I have already procured another Denon receiver and even though it's masochistic and financially ridiculous to repair this unit, even though it was $1,100 when new, I like challenges and I want to learn.

 

[lovinthehd]

Good luck on finding a printed manual with the fold outs and all but you may end up at Kinkos....

 

[TLS Guy]

Gents, I meant to say that I have the proper PDF now, but I am not able to go back in fix my textual error for some reason. I thought I stated the reason that I want a printed copy. The factory publications have nice size, 16 inch by 22 in, fold out schematics. Even if I go to the time and expense to drive to Kinko's to print those pages out properly, I doubt they will still be as nice of the factory publication. Initial tests with the Darlington output transistors, indicate that they are good but I have ordered another transistor tester to double check. The attached picture is of the surface mount transistor which is in the ASODET circuit. It is testing bad in circuit and it looks like it got hot, I don't know what is that red stuff ?

Well that component is certainly blown and given up its vital juices. But the problem with these sort of chases is that what you see is generally effect rather than cause.

I have no idea what the ASODET circuit is.

All I know if that I only service good vintage gear with through board soldering. I personally would not go near a unit like that to try and service it. Even in the service centers repair is by board replacement and when boards are all gone, which is usually too soon, then the units are a recycle job.

If that unit went into protection after a speaker short, I would be truly shocked if the output stage of that power amp is OK. To go into protection there had to be a big over current event, and that most likely occurred in the output stage of the shorted amp. It is that old dictum, "common things commonly happen, rare things seldom".