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

Pass Labs This forum is dedicated to Pass Labs discussion.

Nakamichi PA-7II won't power on, limiter resistor blown
Nakamichi PA-7II won't power on, limiter resistor blown
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 Search this Thread
Old Today, 12:00 AM   #81
Chamberman is offline Chamberman  United States
diyAudio Member
 
Join Date: Jun 2001
Location: USA, Dallas/Ft Worth, Tx
Sorry I should've been more specific on this test. Leave Q116 - Q119 out and power the amp up via DBT. Then measure the voltage on the incoming traces to the bases of Q117 & Q116 to see if the full neg rail is still present. This will isolate the output from the input circuitry and will point to whether the issue is up front or in the back half of the amp.

You'll have to first find the source of the short on B to C of the right ch Q117, 119 though. Perhaps and errant solder splash.

A base to collector short on those would certainly put full neg rail in the wrong place.

You may want to lift one side of R125R to see if it measures properly too.
__________________
KC
  Reply With Quote

Reply


Nakamichi PA-7II won't power on, limiter resistor blownHide 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
Nakamichi PA-7 Power Transformer sourceoneaudio Swap Meet 6 25th March 2018 04:54 PM
Nakamichi PA-7II: Thermofuse in the potted transformer electrafixion71 Pass Labs 31 3rd January 2015 02:31 AM
Limiter Resistor of MOSFET Power Amp ervinl Solid State 11 23rd July 2010 06:55 AM
Nakamichi PA-7II manuals - HELP Peteb Pass Labs 4 4th October 2007 07:09 PM
Nakamichi OMS-7II help proteo01 Digital Source 0 17th September 2007 03:12 AM


New To Site? Need Help?

All times are GMT. The time now is 05:08 AM.


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
Wiki