A friend of mine asked me to help get his A/V receiver up and running. Some guys have tried to fix it, without success.
First informations are as follows:
After an unpredictable time, it goes into protection mode, and only resets if powering off and on.
There is a pair of output transistors missing.
I will post some photos.
Does anyone have schematics for this amp? (I haven't tried to find them as yet).
Thanks for any advice.
Regards,
Max.
First informations are as follows:
After an unpredictable time, it goes into protection mode, and only resets if powering off and on.
There is a pair of output transistors missing.

I will post some photos.
Does anyone have schematics for this amp? (I haven't tried to find them as yet).
Thanks for any advice.
Regards,
Max.
A friend of mine asked me to help get his A/V receiver up and running. Some guys have tried to fix it, without success.
First informations are as follows:
After an unpredictable time, it goes into protection mode, and only resets if powering off and on.
There is a pair of output transistors missing.
I will post some photos.
Does anyone have schematics for this amp? (I haven't tried to find them as yet).
Thanks for any advice.
Regards,
Max.
Channel w/ missing OP's is 'floating" ... triggering protect circuit. Either short that channel out with 1k resistor to ground or fix it. Did this on my 4.1 sony receiver before I "moved on" to DIY.
OS
Some pics...
Thank you OS and Infinia. I was thinking of both situations, and I will manage to execute those procedures.
Attached some pictures.
Regards,
Max.
Thank you OS and Infinia. I was thinking of both situations, and I will manage to execute those procedures.
Attached some pictures.
Regards,
Max.
Attachments
Your main PS capacitors are all bad by the looks of things. (melted sleeves) 

Recapping is a must in this case .. that could be the main problem !!!
It has been along time since I saw an OEM amplifier .. How do they get away with only 8200uF X 2 ??? Mine is 40,000+ X2 !
OS
Recapping is a must in this case .. that could be the main problem !!!
It has been along time since I saw an OEM amplifier .. How do they get away with only 8200uF X 2 ??? Mine is 40,000+ X2 !
OS
Last edited:
I have it in jpeg format, file is quite huge, about 50+ MB, just upload to megaupload, send me a mail if you can't retrieve.
MEGAUPLOAD - The leading online storage and file delivery service
MEGAUPLOAD - The leading online storage and file delivery service
Dear All:
I also have a Pioneer VSX520 A/V receiver but after few of purchasing it goes protection mode and power does not turn on. I found their repair manual and it says that if there is any DC error then the power will not turn on.
To by pass this, press Avd Surr + Power then it will turn on. And mine turns on but after 2 seconds it shuts off again.
Sometimes after pressing those keys and removing the power cord for a certain time it functions normally; again it goes protection mode without any clue! At least for me L
If I enter service mode by pressing some front panel keys, it show the log how many times the error occurred, like DC Error, Overload, Over Temperature etc.
Can you please suggest what might be wrong and what is DC Error ment by Pioneer?
Thanks in advance
Raj
I also have a Pioneer VSX520 A/V receiver but after few of purchasing it goes protection mode and power does not turn on. I found their repair manual and it says that if there is any DC error then the power will not turn on.
To by pass this, press Avd Surr + Power then it will turn on. And mine turns on but after 2 seconds it shuts off again.
Sometimes after pressing those keys and removing the power cord for a certain time it functions normally; again it goes protection mode without any clue! At least for me L
If I enter service mode by pressing some front panel keys, it show the log how many times the error occurred, like DC Error, Overload, Over Temperature etc.
Can you please suggest what might be wrong and what is DC Error ment by Pioneer?
Thanks in advance
Raj
For those looking for the service manual, here are two working links:
Pioneer VSX-9500S | Owners Manual, Service Manual, Schematics, Free Download | HiFi Engine or
PIONEER VSX-9500S VSX-7500S Service Manual free download, schematics, eeprom, repair info for electronics
Pioneer VSX-9500S | Owners Manual, Service Manual, Schematics, Free Download | HiFi Engine or
PIONEER VSX-9500S VSX-7500S Service Manual free download, schematics, eeprom, repair info for electronics
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