Denon avr 2802 with no sound on speaker

[klementor]

Re: Denon avr 2802 with no sound on speaker

Hi guys. First of all, I express my gratitude to everyone for this information. I also repaired my Denon AVR-2802. I changed only Flash: Atmel AT49LV002-70TC. The DSP is working fine. I took the firmware here on the forum. I ordered memory chips on Aliexpress. I ordered 3 pieces. Two were faulty and were used. Link to the seller https://aliexpress.ru/item/100500211...00018803732901

[fox_tango]

I found this thread and it describes my symptoms exactly. I located the DSP chips on e-bay and just got done replacing it. I put a "surgical drape" of aluminum foil and capton tape around the DSP and used my hot air gun to remove the old chip from the board. I thought about cutting the legs one at a time then cleaning up the mess with my soldering iron, but am happy that I tried the hot air first. It came off quickly with no issues. I did remove the tall electrolytic caps from the area first to get rid of obstacles.



New chip installed:


Unfortunately, my symptoms remain.

I've reviewed the previous posts here and am not able to locate the flash ROM data contents file. I think this is my next step. I'm not sure if the previous posters are following this thread anymore, but I'd like to request help obtaining the flash file, as well as any leads on the flash memory device. I've come this far, I really want to try to get this unit back up and running.

Thanks all for reading and for any advice you can offer.

[azchris]

Hi, Fox Tango. Glad to hear you are making some progress with your Denon.
Please see my reply on 2-10-2018 where I posted pretty much everything you should need including the ROM file for the Flash IC.
The ROM hex file still seems to be available for download; it's in the zip file attached to that posting.
As I said in that post, I used a Macronix MX29LV040CTI-70G (4Mbit 512k x 8) FLASH IC and Digikey still has it in stock (see my post for the link
https://www.digikey.com/en/products/...TI-70G/2744774
Of course, the FLASH IC comes blank so it needs to be programmed. I still have my programmer and I can program the FLASH IC with the hex file
but I don't currently have any more of the macronix chips on hand.

Chris/azchris

[fox_tango]

Success!! It was my flash chip! As I mentioned previously, I swapped out the DSP chip and my symptoms stayed exactly the same. So, I replaced the flash IC and I have a perfectly working Denon 982 again! I'm am so grateful for everyone who contributed to this thread and provided the information. A special thanks goes out to azchris! I ordered the required flash chip from Digikey and azchris agreed to program it for me.

To make the repair, I used mostly the same procedure as before. I made a heat resistance surgical drape from kapton tape and foil. I used my heat gun to heat the flash chip until the solder went molten, and picked it off with tweezers. Then cleaned the pads with solder wick and denatured alcohol. Finally, I soldered the flash IC back on by hand with a fine tip soldering iron. I did manage to create a few bridges on the fine pitch leads, but cleaned it off with the solder braid and all was well.

To recap my symptoms, it was very faint audio, only audible with volume maxed out, and then if any input source was changed, audio was completely dead. Fix was replacing the DSP and flash IC.

[Agent24]

Nice fix!

Make sure you have a copy of that EEPROM data in case you need to reprogram it again!

[saviabr]

Re: Denon avr 2802 with no sound on speaker

Hello,
I am a small French hacker, sorry for the translation ...
The idea for me was to repair my DENON AVR-2802 without buying a memory or programmer

Hi, friend! I liked your idea. I also have an Arduino mega 2560 lying in my closet unused.
Could you send me a diagram of your Arduino programmer and W29C020 memory connections.
This would help me a lot. Thank you!

[Robert85]

Hello, I also have this problem with a Denon AVR2802 related to the sound, I downloaded the bin posted on the forum but I can't write it along the way, an error appears, am I not doing something right or is there something else, I used the AT49LV002 as the one in the device, I tried several pieces but without results, I use TL866 for programming.

[Robert85]

Greetings again, I see that there are not many new posts on this issue, but I'm back with news, I managed to bring back to life 2 such devices with the ideas from this forum, everything boils down to the quality of the parts, by buying quality parts I managed to program the flash,

[Astaloki]

Re: Denon avr 2802 with no sound on speaker

Hi,

I found my Denon AVR2802 had failed in the way described above. However I noticed that in some situations (detailed below) I could hear very faint audio coming through the amp.

If you would like to re-use the following functionality of your amp then there is a fairly easy fix. With the ‘fixed' unit I can:

•Use the amplifier to amplify an external (analogue) source
•Volume control works
•Muting works
•Power speakers A and or B, and potentially surround and sub as separate channels (have not tested)

What does not work:
•The radio receiver
•Switching to any other sources
•Video switching (untested)


Step 1 - confirm your amp has the same fault symptoms as mine had:

A.Connect a source to the FL/FR EXT. IN inputs (e.g. phone, MP3 player, computer) [img]
B.Connect speakers to the FR/FL outputs
C.Configure the ‘source' to be EXT.IN
D.Turn up the volume to around 0dB - you should hear nothing.
E.Turn off the amp and turn it back on
F.Only adjust the main volume, turning it gradually up to +18db - you should hear the EXT.IN source signal coming faintly out the speakers.
G.Note if you do any other adjustment to sources at this point then you will have to power-cycle the system.



Step 2 - disable the mute which is in place

There are a couple of places in the audio signal path that the system can mute the sound. Some are electronic and some are electromechanical (i.e. relays). I think what was happening on my system was that because the main DSP was failing (probably due to the ROM failing as described elsewhere) the microcontroller was then muting the signal. The electronic mute used is not infinite, hence why the test in step 1 works. In this step we disable the mute (permanently).

A.Power off the amp
B.Take off the top case (as described in the service manual)
C.Unscrew the back panel (a lot of screws!)
D.Remove the DSP card to give access to connecter CX114 on the base PCB. [img]
E.Use a solder blob to short pins 3 and 4 of this connector. [img]

Step 3 - test

A.Re-attach “EXT.IN” inputs to test and feed in a signal
B.Power on the amp and slowly increase main volume from lowest volume.
C.If this fix has been successful then you will hear sound from your speakers when the main volume is much lower that in step 1.
D.Having confirmed the fix, reassemble the unit (you could run it permanently without the failed DSP board).
E.Enjoy a few more years out of your amp instead of dumping it!


Note: even with this fix any change to the ‘source' will cause the amp to mute until it is power cycled. This functionality works for me (I only use one internet-connected source into my amp) but may not work for you. No DSP or digital functions (like DTS, Dolby, etc) are available. If you need the DSP then consider replacing the ROM as detailed elsewhere.

The above steps worked for me and my Denon avr-2802 is making sounds once again.

Thanks so much to dbdenon for his time and effort in creating this work around.