Go Back   Home > Forums > >

Pass Labs This forum is dedicated to Pass Labs discussion.

Amp Camp Amp - ACA
Amp Camp Amp - ACA
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
Reply
 
Thread Tools
Old 14th October 2021, 07:27 PM   #11001
captain pugwash is offline captain pugwash  United Kingdom
diyAudio Member
 
Join Date: Feb 2007
Location: Stevenage, Hertfordshire
45.5 ohms with red lead on G, 45.6 ohms the other way. Thats with the board off of the heatsink
  Reply With Quote
Old 15th October 2021, 05:17 AM   #11002
Mooly is offline Mooly  United Kingdom
diyAudio Moderator
 
Mooly's Avatar
 
Join Date: Sep 2007
Amp Camp Amp - ACA
I'm wondering if that upper FET is zapped. It would be a very unusual failure mode but the reading seems to suggest it. It would give the overall voltage readings you are seeing with the fault.

I would replace that one FET making sure it is properly attached to the heatsink (but do not overtighten them though).
  Reply With Quote
Old 15th October 2021, 06:34 AM   #11003
Loudthud is offline Loudthud  United States
diyAudio Member
 
Loudthud's Avatar
 
Join Date: Nov 2007
Location: Near Dallas Texas USA
Perhaps others will chime in ... back in the late 80's I worked at a place that used lots of the IRF hexfets. They almost always failed as dead shorts. I cut a couple of TO-3s open and all you would see is a small black spot somewhere on the top of the die. I suspect Q3, the NPN ZTX450 or C2 the 1000uF cap.
  Reply With Quote
Old 15th October 2021, 07:57 AM   #11004
Mooly is offline Mooly  United Kingdom
diyAudio Moderator
 
Mooly's Avatar
 
Join Date: Sep 2007
Amp Camp Amp - ACA
If it has just failed G to S then I think that would be unusual tbh. Q3 and C2 were my first thoughts but they have been eliminated.

Quote:
Originally Posted by captain pugwash View Post
Just checked C2 and Q3, all ok.
  Reply With Quote
Old 15th October 2021, 02:19 PM   #11005
captain pugwash is offline captain pugwash  United Kingdom
diyAudio Member
 
Join Date: Feb 2007
Location: Stevenage, Hertfordshire
Quote:
I'm wondering if that upper FET is zapped. It would be a very unusual failure mode but the reading seems to suggest it. It would give the overall voltage readings you are seeing with the fault.

I would replace that one FET making sure it is properly attached to the heatsink (but do not overtighten them though).
__________________
Sounds like a plan, thought I had some spares but don't, need to order pronto.
  Reply With Quote
Old 15th October 2021, 05:27 PM   #11006
Mooly is offline Mooly  United Kingdom
diyAudio Moderator
 
Mooly's Avatar
 
Join Date: Sep 2007
Amp Camp Amp - ACA
lets hope that does the trick.
  Reply to this post

Reply


Amp Camp Amp - ACAHide this!Advertise here!
Thread Tools

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
Amp Camp Amp #1 Nelson Pass diyAudio.com Articles 54 8th May 2018 03:13 AM
Amp Camp! Jason Site Announcements 2 30th June 2012 02:57 PM
Best D camp config for Tweeter amp Zero One Class D 0 24th February 2010 04:57 AM
better the Pass camp? rick57 Tubes / Valves 6 26th March 2005 06:04 AM


New To Site? Need Help?

All times are GMT. The time now is 09:27 AM.


Search Engine Optimisation provided by DragonByte SEO (Pro) - vBulletin Mods & Addons Copyright © 2021 DragonByte Technologies Ltd.
Resources saved on this page: MySQL 14.29%
vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2021 DragonByte Technologies Ltd.
Copyright ©1999-2021 diyAudio
Wiki