• The move to the new server is done. There are some software and database maintenance updates in process. This has us passing the hat around to help out. We appreciate any donations. Seriously, even a dollar helps. The payment page may be found here - https://www.audiokarma.org/support.html

Denon AVR-3801 power problems and more...

Devileyes

Member
Ok, so I owned this Denon AVR-3801 since it was new. After using it for a few years with it always running perfect, my house was hit by lightning. Long store short, it was dead. Brought it to a repair shop and the tech there (very good and reputable tech) fixed it for me. I believe he had to replace the micro processor.
Anyway, I used it for a few years without any problems. Then I started losing output if I would switch input (going from dvd to cd, etc...) The only way to get output back was to press the test tone and then output would come back after the test tone was shut off. I got tired of this and bought another receiver. I stored the Denon, hoping someday to maybe fix it myself. So I pulled it out of storage the other day and it’s completely dead, no power, no lights, nothing. So I took the cover off and started to check things it may be, power cord, fuse in cord, checked all the fuses, checked the power switch, everything checked good. No burnt spots on boards, no bulging caps....it all looks good, but no power.
So anyway I was flipping it back over to place it on its feet, as I was taking the bottom screws out for the face plate and it slipped out of my hand and one side dropped a few inches and slammed onto my workbench. Well now we got power! Of course once I shut it down to hook up speakers and a CD player it wouldn’t power up again. So I dropped it (lightly) again and got it to power up again, but it still has the output problems and now distorted sound.
I remember reading in a thread here about a certain brand of amp or receiver that people would have to drop from 2 or 3 inches to get to work... possibly due to a cold solder joint...but I cannot find the thread again.
Could this be the problem with this unit? Cold solder joint somewhere? Is it possible that is also causing the problem with the output issue and distorted sound? Or is it most likely multiple problems with the receiver?
Thanks,
Joe
 
Register to hide this ad
check the pcbs mounting screws.. one or more is a chassis ground on the main board check other boards too. tighten all the chassis assembly screws too. Yes aged solder joints may be possible also loose wire connectors.
 
Last edited:
check the pcbs mounting screws.. one or more is a chassis ground on the main board check other boards too. tighten all the chassis assembly screws too. Yes aged solder joints may be possible also loose wire connectors.
Thanks for the fast reply!
I went ahead and tightened all the mounting screws and chassis screws. All were pretty tight, just a few with a small amount of movement. Then I double checked all the wire connectors. Plugged it back in and still no go.
So then I started trying the power button while pressing down on each individual vertical board, got to 6th board of the 7 and it powered up!
I cycled the power a few times, then let it sit off for awhile. When I tried again still no power, unless I push down on that 6th board.
The board looks to be seated in its connectors right.
But at least I narrowed it down to that area.
I’m adding pics of what board I need to press down on.310D6320-4861-4759-AF46-1395AD3CE422.jpeg994E7F5D-93C1-4047-AF20-BA223569CC9D.jpeg
 
Ok looking over the suspected problematic board.
Do the the two solder joints I’ve pointed out in the picture look to be suspect?
If they are, I don’t think I’ve got the know how or steady enough hands to try and fix them...544B7966-2C80-48D4-A39D-81D5882385D9.jpeg
 
I figured it out
Joints just need a tad of flux and solder to reflow those and the other I saw I marked in red. If no joy?? look at it this way. these avr's are not worth much money now days.
upload_2021-1-18_21-13-14.png
I spent two months chasing a rabbit, a free avr given to me, and swore I'd never mess with one again after I figure out that the main board had a micro crack from dropping by somebody. But I learned a lot how they work.
 
btw comparing those joints to adjacent joint in your pic? they all need a fast quick touch up. quick like duck in and out and that might not yield anything.
upload_2021-1-18_21-21-52.png
 
btw comparing those joints to adjacent joint in your pic? they all need a fast quick touch up. quick like duck in and out and that might not yield anything.
View attachment 2102157
Ok, Thank you! I need to order some flux.
I’ve got a new soldering station, new desoldering gun, new solder, a bunch of tips...but no flux!
Yeah, I pulled this AVR out to get some experience, and maybe learn something. If I can fix it...great!
If I can’t....well, I’m already learning....so I’m accomplishing what I want. :)
I know these AVR’s aren’t worth much, but I enjoyed this Denon and I very much liked it’s sound.
Plus it’s a Euro model with the Gold face, so I really like the look of it too.759BBE06-A8F9-4EDE-9E39-C3C43BB110BB.jpeg
 
Back
Top Bottom