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
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.
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
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
Thanks... now you mention it I remember.
Have you tried Cambridge Audio in the UK,
Cambridge Audio Customer Care Centre
Hello,
Replaced all damage material...also burned 7805. Now is working fine.
With Pic connected amp just turn speaker relay on... disconnected pic connector ,then turn also power amplifier on...but without logic board working the mute relay stays off...
The PIC is 100% damaged.
I have also send mail to Cambridge Audio Customer Care Team.
The answer was...
Query History
Dear Sir, thanks for your inquiry.
I'm not allowed to send information like this directly. I have made the service manager aware and he will see what the delay might be.
Regards
Ed Selley
And that was all and no other information anymore.
Thank you.
Replaced all damage material...also burned 7805. Now is working fine.
With Pic connected amp just turn speaker relay on... disconnected pic connector ,then turn also power amplifier on...but without logic board working the mute relay stays off...
The PIC is 100% damaged.
I have also send mail to Cambridge Audio Customer Care Team.
The answer was...
Query History
Dear Sir, thanks for your inquiry.
I'm not allowed to send information like this directly. I have made the service manager aware and he will see what the delay might be.
Regards
Ed Selley
And that was all and no other information anymore.
Thank you.
Response from Cambridge Audio is that the pre-programmed PICs are still available from their UK suppliers. I can order them if you would like me to.
You can refer to their e-mail directly if you would like to.
http://support.cambridgeaudio.com/
Dear Mr Freestone,
Your query #109496 has been updated by the Cambridge Audio Customer Care Team.
To view the reply please log in at http://support.cambridgeaudio.com
Query History
Dear Sir, thanks for your inquiry.
This should be available from the Richer Sounds Service Department;
http://www.richersounds.com/information/service
Regards
Ed Selley
Can I still obtain either a replacement pre-programmed PIC for the Azur 640A or can I download the .HEX file for a DIY PIC replacement.
Best regards,
Cambridge Audio Customer Care Team
This e-mail is confidential and for the addressee only. Please refer to Disclaimer for important notices.
Copyright © www.support.cambridgeaudio.com
You can refer to their e-mail directly if you would like to.
http://support.cambridgeaudio.com/
Your query #109496 has been updated by the Cambridge Audio Customer Care Team.
To view the reply please log in at http://support.cambridgeaudio.com
Query History
Dear Sir, thanks for your inquiry.
This should be available from the Richer Sounds Service Department;
http://www.richersounds.com/information/service
Regards
Ed Selley
Ed Selley - 17/10/2013 00:50
Andrew Freestone - 16/10/2013 18:18
Best regards,
Cambridge Audio Customer Care Team
This e-mail is confidential and for the addressee only. Please refer to Disclaimer for important notices.
Last edited:
Cambridge audio Ca640a v2 help
Hello,
I finally get it....HEX file cost ne about 50euro ...
My friend prigramed PIC, and meanwhile a also changed resonator, 2 transistors,
74HC4094.
Result...
After turn on main switch all the signal lights on front panell are turned on but thats all... i still can*t switch the amp on.
Can anybody have an idea what could be wrong.
If anybody need hex file, can send me PM.
I can send you schematic if somebody need it
It can alse be downloaded from
CAMBRIDGE AZUR-540A V2.0 SM Service Manual free download, schematics, eeprom, repair info for electronics
540 and 640a V2 are almost identical amplifiers.
Thank you.
Hello,
I finally get it....HEX file
cost ne about 50euro ...My friend prigramed PIC, and meanwhile a also changed resonator, 2 transistors,
74HC4094.
Result...
After turn on main switch all the signal lights on front panell are turned on but thats all... i still can*t switch the amp on.
Can anybody have an idea what could be wrong.
If anybody need hex file, can send me PM.
I can send you schematic if somebody need it
It can alse be downloaded from
CAMBRIDGE AZUR-540A V2.0 SM Service Manual free download, schematics, eeprom, repair info for electronics
540 and 640a V2 are almost identical amplifiers.
Thank you.
Cambridge Ca640 V2
Fix the amp!
Try to reprogramed Pic once again and worked.
If anybody is interested in modification of that amp... it is worth it.
I have talked to German firm that modified CA640 and V2 and....
We discussed about it...and i have manual how to improve CA640 v2
Opamps, resistor, gain, capacitors, maby new transformer for +/-15V ...
I have modified one... big improvement. I have put 3 different buffer opamps at first stage for personal best sound... it is interesting
All opamps don*t work at that place... Gain is too high and vol. pot. is average, so at low level fine volume setting is impossible...to many decoupling capacitors, vishay resistors, simlimc2, Panasonic fc, Muse at amplifier input....
First picture... that is how it was at the beginning, second and third after cleaning and modification.
Nice greet
Fix the amp!
Try to reprogramed Pic once again and worked.
If anybody is interested in modification of that amp... it is worth it.
I have talked to German firm that modified CA640 and V2 and....
We discussed about it...and i have manual how to improve CA640 v2
Opamps, resistor, gain, capacitors, maby new transformer for +/-15V ...
I have modified one... big improvement. I have put 3 different buffer opamps at first stage for personal best sound... it is interesting
All opamps don*t work at that place... Gain is too high and vol. pot. is average, so at low level fine volume setting is impossible...to many decoupling capacitors, vishay resistors, simlimc2, Panasonic fc, Muse at amplifier input....
First picture... that is how it was at the beginning, second and third after cleaning and modification.
Nice greet
Attachments
My friend has Azur 650 amp with exactly the same problem! The local service center refused to repair it under warranty period as the damage was due to power fluctuation according to them. Anyways now the warranty period is also over.
Will be contacting you soon once I get my hands on the amp.
. Anyways now the warranty period is also over.Will be contacting you soon once I get my hands on the amp.
Last edited:
Ca 540V2 DCoffset
Hello,
No problem with that, first you replace damaged material and by a new pic and i will help you with hex file.
I have another Cambridge audio Ca540V2 amp at home. I have made some improvements but i have one question.
At no load the primares are 31 and 33,4V and after recitifer 41,2 and 44,5V.
And DC offset is around 800mV at both channels.
Have anybody any idea how to fix that... or must I assembling the toroid and unwreathe few turns to get 31V at other secondaries to?
Amp is working and it doesn*t go into protection, but for my feeling the DC offset is tooo high.
thank you Davorin.
Hello,
No problem with that, first you replace damaged material and by a new pic and i will help you with hex file.
I have another Cambridge audio Ca540V2 amp at home. I have made some improvements but i have one question.
At no load the primares are 31 and 33,4V and after recitifer 41,2 and 44,5V.
And DC offset is around 800mV at both channels.
Have anybody any idea how to fix that... or must I assembling the toroid and unwreathe few turns to get 31V at other secondaries to?
Amp is working and it doesn*t go into protection, but for my feeling the DC offset is tooo high.
thank you Davorin.
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