Crown D-150 series II IOC light on - diyAudio
Go Back   Home > Forums > Amplifiers > Solid State

Solid State Talk all about solid state amplification.

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 1st April 2005, 07:53 AM   #1
Mikelg is offline Mikelg  United States
diyAudio Member
 
Join Date: Mar 2005
Location: Tifton, Georgia
Send a message via Yahoo to Mikelg
Default Crown D-150 series II IOC light on

It has been quite a while since I have done any bench work. I have ordered a service manual for a Crown D-150 series II Amp I bought. Channel 2 seems to work, channel 1 does not. When I power up the amp the IOC light is on for channel 1. The serial number of my amp is: 056605 Any suggestions on where I should look first? Any help would be greatly appreciated. Thanks Mike
  Reply With Quote
Old 1st April 2005, 08:02 PM   #2
diyAudio Member
 
Join Date: Apr 2005
Location: Toronto, Ontario
I think I have service manuals for D150A Series I and IC150A.

I don't recall seeing much for trouble shooting tips.

IOC stands for "Input Output Comparator"

It is intended to turn on led when input differs slightly from ouput based on distortion (clipping of output waveform). Circuit has pulse stretcher to allow flashes to be visable on short transients.

D150A design is supposed to be short circuit tolerant.
However, with no output I would check output transistors first, followed by drivers.
  Reply With Quote
Old 1st April 2005, 08:28 PM   #3
Account Disabled
 
Join Date: Aug 2004
Location: Earth
This was a chip (I think LM833) driven amp whose greatest design weakness, in my opinion, was an unbiassed output stage. I repaired a few used for PA systems way back. Always the power transistors and sometimes the drivers.

Were they 2N3584 and 2N6421 both TO66.
  Reply With Quote
Old 1st April 2005, 08:55 PM   #4
moamps is offline moamps  Croatia
diyAudio Member
 
Join Date: Oct 2002
Location: Croatia
on-line service manual

http://www.crownaudio.com/gen_htm/legacy/legacamp.htm
  Reply With Quote

Reply


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
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
Crown IC 150 power light mummy Solid State 1 7th February 2009 11:27 PM
Crown D-Series Bridge Mono Modification dakine Solid State 4 5th February 2009 06:50 PM
Crown Com-Tech 210 Power Amplifier Crown Com-Tech 210 tyler477 Solid State 1 31st October 2008 04:24 AM
WTB: AMCRON / CROWN DC300 Series II Jan Dupont Swap Meet 0 23rd April 2005 08:32 PM
Cambridge Crown Series specifications Toshito Multi-Way 1 21st December 2002 01:22 PM


New To Site? Need Help?

All times are GMT. The time now is 12:38 AM.


vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2014 DragonByte Technologies Ltd.
Copyright 1999-2014 diyAudio

Content Relevant URLs by vBSEO 3.3.2