Go Back   Home > Forums > >
Home Forums Rules Articles diyAudio Store Blogs Gallery Wiki Register Donations FAQ Calendar Search Today's Posts Mark Forums Read

Solid State Talk all about solid state amplification.

Denon pma-1080 cutoff after few mins.
Denon pma-1080 cutoff after few mins.
Please consider donating to help us continue to serve you.

Ads on/off / Custom Title / More PMs / More album space / Advanced printing & mass image saving
Thread Tools Search this Thread
Old 11th August 2009, 10:13 PM   #1
Andreash is offline Andreash  Norway
diyAudio Member
Join Date: Jan 2005
Location: Bergen
Default Denon pma-1080 cutoff after few mins.


I recently bought an well used Denon pma-1080.
But i have some problems. The output is cut off after a few minutes when started from cold.

If I change inputs i can clearly hear that the relays doesn't click as they should. I can also blow into the cabinet left side, behind the transformer and it gets back on.

But if I switch off/on a few times, the amplifier can be ok for the rest of the day.

Do anyone have service manual for this amp. or suggestions in where to start looking for error..

best regards
  Reply With Quote
Old 11th August 2009, 11:23 PM   #2
jaycee is offline jaycee  United Kingdom
diyAudio Member
Join Date: Apr 2004
Location: Norwich, UK
check for cracked solder joints
  Reply With Quote
Old 31st August 2009, 08:46 AM   #3
Andreash is offline Andreash  Norway
diyAudio Member
Join Date: Jan 2005
Location: Bergen
Default solder joints


I've checked for solder cracks, and found a few.. But the problem is still present..

there are some resistors that get hot on the relay-board for the outputs, and those had cracked slodering.

And the board also had evidence from liquid spills..

Do anyone have some schematics for this amp, or a closely related amp? i.e PMA 980R ??
Or where can I get one?

Best regards
  Reply With Quote
Old 3rd September 2009, 09:33 PM   #4
Jakobsson is offline Jakobsson  Sweden
diyAudio Member
Join Date: Apr 2009
Maybe the relays are bad.
Measure the power to the relays.
I have 2 denons on is a 980r but i only had a output transistor problem on that one.
Alot of old Marantz from the same time era got relay problems.
I have just bought a defective pma-1560 which turns itself off ,clicks when you try to turn it on.
I will receive this amp early next week and maybe i can give you some idea to your problem.
Optical class A is great.

  Reply With Quote
Old 4th September 2009, 02:10 PM   #5
tricomp is offline tricomp  Denmark
diyAudio Member
Join Date: May 2004
Location: Jutland
Hej Andreas,

Send mig en PM med din e-mail adresse.
Jeg kan hjælpe med service-manualen og måske også med et par forslag til, hvad der kan være galt.

Med venlig hilsen

  Reply With Quote
Old 6th September 2009, 08:01 PM   #6
MatsE is offline MatsE  Aland Islands
diyAudio Member
Join Date: Jul 2008
I have a PMA-1080R that I bought used some years ago, and I have had many problems with the relays.

First, the sound in the right channel faded away now and then. I found that the contacts in the output relay were burnt and measured tens of ohms when they were closed. Cleaning the contacts helped for a while, but later I just bypassed the output relays. Which of course disables the protection circuits and muting.

I also had problems with Source Direct. The signal was lost in both channels, if I remember correctly. Never found the cause. I stopped using Source Direct.

  Reply With Quote


Denon pma-1080 cutoff after few mins.Hide this!Advertise here!
Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
Schematics of NAD 208 & Rotel 1080/1090 wanted! Ultima Thule Solid State 33 18th June 2012 02:38 AM
Pioneer SX-1080 not working for sale jeffshort2000 Swap Meet 0 24th November 2007 08:57 PM
popping crackling distortion that clears up after 2 mins Help!! Puggie Solid State 7 11th October 2006 12:13 PM
1st ever project finished 2 mins ago - IT PLAYS!! gilbodavid Class D 7 3rd November 2005 10:32 PM

New To Site? Need Help?

All times are GMT. The time now is 03:27 PM.

Search Engine Optimisation provided by DragonByte SEO (Pro) - vBulletin Mods & Addons Copyright © 2018 DragonByte Technologies Ltd.
Resources saved on this page: MySQL 16.67%
vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2018 DragonByte Technologies Ltd.
Copyright ©1999-2018 diyAudio