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.

signal after power switched off
signal after power switched off
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 6th August 2014, 02:43 AM   #11
Enzo is offline Enzo  United States
diyAudio Member
Join Date: Sep 2004
Location: Lansing, Michigan
I tend to not think both channels have the same problem, so I look to something they share.

Sorry, but you don;t have the mute button on do you? My first thought is a mute circuit hanging up.

Isolate the problem. The block diagram seems to say there is a preamp out jack and a couple power amp in jacks. So with the amp running and showing the silent symptom, plug a signal into the power amp in jack, anything come out the speakers? Likewise put a signal into one of the source jacks, and set the controls as you would, then monitor what comes out the preamp out jack. Those two tests should tell usw which half of the amp has the problem.

Elektrotanya has the schematic, though some of the scan is poor. When you get to their page, look just under the cover image and it says "processing". Wait 30 seconds until it changes to "Get Manual" and then click there. All those big green DOWNLOAD buttons are for other stuff.

NAD 3140 Service Manual free download, schematics, eeprom, repair info for electronics
  Reply With Quote
Old 6th August 2014, 04:07 AM   #12
shredhead is offline shredhead  United States
diyAudio Member
shredhead's Avatar
Join Date: Aug 2011
Location: NC
If the power rails are good with no offset I'd guess it's a messed up protection circuit.
  Reply With Quote
Old 6th August 2014, 04:32 AM   #13
rettedm is offline rettedm
diyAudio Member
Join Date: Sep 2011
Default No sign of life

The plot thickens. Protect kicked in and now no power.
  Reply With Quote
Old 6th August 2014, 06:09 AM   #14
djk is offline djk
djk's Avatar
Join Date: Feb 2001
Location: USA
Check the muting circuit with the J-FETs.
Candidates for the Darwin Award should not read this author.
  Reply With Quote


signal after power switched offHide 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
Switched power supplies better sometimes? lorienblack Power Supplies 5 4th January 2014 08:06 PM
power but not switched on? redrooster Solid State 0 14th August 2010 01:59 PM
switched-mode power suppies Dimitar13 Everything Else 0 19th February 2008 12:50 AM
Switched power supply? Johan_Ch Tubes / Valves 38 31st January 2004 11:53 AM
Switched mode power supplies Magura Parts 13 3rd January 2004 05:44 PM

New To Site? Need Help?

All times are GMT. The time now is 09:36 PM.

Search Engine Optimisation provided by DragonByte SEO (Pro) - vBulletin Mods & Addons Copyright © 2020 DragonByte Technologies Ltd.
Resources saved on this page: MySQL 15.00%
vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2020 DragonByte Technologies Ltd.
Copyright ©1999-2020 diyAudio