Cambridge Audio Azur 640a problem - diyAudio
Go Back   Home > Forums > Amplifiers > Chip Amps

Chip Amps Amplifiers based on integrated circuits

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 2nd June 2013, 02:02 AM   #1
diyAudio Member
 
Join Date: Jun 2013
Default Cambridge Audio Azur 640a problem

There is an intermittent problem with the speaker output. When switching between input source there is either no sound or it only comes out of one channel (can be either) or it works properly.

When pressing the input selector button there is the expected audible (relay?) click inside the amp. If I keep switching between inputs it will eventually work although sometimes one channel can drop out later. It seems to work better if it is warmed up. It's been happening for years but is getting worse to the point of unusable. Can take 20 or more switches to work.

I only use one input channel and have moved the RCA's around all 4 inputs with no improvement.

Is this something easily (cheaply) fixed by a technician or is a new amp (AU$500) the solution?
Cheers
  Reply With Quote
Old 2nd June 2013, 01:50 PM   #2
AndrewT is online now AndrewT  Scotland
diyAudio Member
 
Join Date: Jul 2004
Location: Scottish Borders
Possibly dirty contacts in the selector switch/es
Disconnect from the mains power.
Inject switch cleaner inside the switch and operate repeatedly.
Allow time for all the solvent to evaporate before considering reconnecting to the mains.
__________________
regards Andrew T.
  Reply With Quote
Old 11th June 2013, 04:45 PM   #3
diyAudio Member
 
Join Date: Jun 2013
I have a similar problem with my Azur 640a. In my case it's a contact issue in the balance dial. It just needs to be re-welded.
  Reply With Quote
Old 11th June 2013, 05:13 PM   #4
Mihkus is offline Mihkus  Estonia
diyAudio Member
 
Mihkus's Avatar
 
Join Date: Jul 2012
Welding PCB boards is the ,most epic thing ive ever heard.
Only possible in china
  Reply With Quote
Old 11th June 2013, 05:45 PM   #5
diyAudio Member
 
Join Date: Feb 2013
Location: CRO
Send a message via Skype™ to overall feedback
Quote:
Originally Posted by Peeb View Post
There is an intermittent problem with the speaker output. When switching between input source there is either no sound or it only comes out of one channel (can be either) or it works properly.

When pressing the input selector button there is the expected audible (relay?) click inside the amp. If I keep switching between inputs it will eventually work although sometimes one channel can drop out later. It seems to work better if it is warmed up. It's been happening for years but is getting worse to the point of unusable. Can take 20 or more switches to work.

I only use one input channel and have moved the RCA's around all 4 inputs with no improvement.

Is this something easily (cheaply) fixed by a technician or is a new amp (AU$500) the solution?
Cheers
Indeed it could be cold solder, try resold contacts on input signal path, relay included if exist there.
  Reply With Quote
Old 15th October 2013, 05:57 PM   #6
diyAudio Member
 
Join Date: Mar 2007
Location: Maribor
Hello,

I will ask here, and i am sorry if this is the wrong place.
I am owner of Cambridge audio amplifier 640v2
After 7 years stops working.... some material was blown...including 7805 and....programed PIC controller. I have contacted original service for spare part and also direct Cambridge audio, but nobody want to help me... i wait and wait but no answer. Cambridge support says that they are not competent to give this info...
Can anybody help me please!!!!
I need Programed PIC... in service manual is written...

PY635 PIC16F721/SP Flash PIC micro Factory part4116-720054-200 1 U2
U2 must be programmed
with AP18951/1 software
(file name: 640AV2.hex)
Request from UK Office

Ok go step by step...if somebody have 640AV2.hex file is also enough because i know somebody who can programme me PIC...
The next possibillity is that somebody who have 640V2 try to copy Firmware from original PIC... if it is not protected to read...i hope so...because i am sure that is protected to written.

I am very gratefull for any help or any kind of information of this PIC spare part.

Davorin Slowenia
  Reply With Quote
Old 15th October 2013, 06:03 PM   #7
Mooly is offline Mooly  United Kingdom
diyAudio Moderator
 
Mooly's Avatar
 
Join Date: Sep 2007
I think the chances of anyone just having a hex file for the PIC are non existent tbh.

Surely the part is available when ordered via the part number in the manual.

Although your PIC is faulty is there any chance that the data can still be read... worth trying maybe.
__________________
-------------------------------------------------------
A simulation free zone. Design it, build it, test it.
  Reply With Quote
Old 15th October 2013, 06:17 PM   #8
diyAudio Member
 
KatieandDad's Avatar
 
Join Date: Nov 2011
Location: UK
Mooly, most PICs have a protection bit that stops anyone reading and stealing the code from them.

Cambridge Audio might have the .HEX file though.
  Reply With Quote
Old 15th October 2013, 06:21 PM   #9
diyAudio Member
 
Join Date: Mar 2007
Location: Maribor
Hello...

Any idea where??? original service in Slowenia can not get it...
Maybe some diy servicer or member of diy who repaire audio equipment.
Pic is dead, supply and gnd is in conntact....therefore te 7805 is hot in 10sek.

Thank you
Davorin
  Reply With Quote
Old 15th October 2013, 06:32 PM   #10
Mooly is offline Mooly  United Kingdom
diyAudio Moderator
 
Mooly's Avatar
 
Join Date: Sep 2007
Quote:
Originally Posted by KatieandDad View Post
Mooly, most PICs have a protection bit that stops anyone reading and stealing the code from them.

Cambridge Audio might have the .HEX file though.
Thanks... now you mention it I remember.

Have you tried Cambridge Audio in the UK,
Cambridge Audio Customer Care Centre
__________________
-------------------------------------------------------
A simulation free zone. Design it, build it, test it.
  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
Cambridge Audio 640A Overheating / Distortion nickalmond Solid State 40 17th May 2013 12:46 AM
Cambridge Audio Azur 640A v2 problem kynsi Solid State 3 9th October 2011 10:15 PM
Cambridge Azur 640A V1 Buzz leviathon Solid State 9 20th June 2010 11:18 PM
Cambridge Audio 640A V2 - service manual Paolo.n Solid State 0 7th July 2009 11:19 AM
Cambridge Audio Azur 640A toroidal power transformer (115V) limono Swap Meet 1 25th December 2008 04:57 PM


New To Site? Need Help?

All times are GMT. The time now is 11:58 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