• The move to the new server is done. There are some software and database maintenance updates in process. This has us passing the hat around to help out. We appreciate any donations. Seriously, even a dollar helps. The payment page may be found here - https://www.audiokarma.org/support.html

Pioneer Spec 2 Protection issue

C

Countdown

Member
Hi all,

I have been going thru this unit and narrowed my issue down to the amplifier board. I’m kinda lost at this point. Essentially the unit will work, play fine, and if you shut it down and turn it back on within a minute, it will go into protection mode. This only happens in one channel.

If you end up waiting like 30 mins it will end up working just fine . Any suggestions? I’ve pretty much replaced and tested every component on the board.
 
Register to hide this ad
Countdown said:
Hi all,

I have been going thru this unit and narrowed my issue down to the amplifier board. I’m kinda lost at this point. Essentially the unit will work, play fine, and if you shut it down and turn it back on within a minute, it will go into protection mode. This only happens in one channel.

If you end up waiting like 30 mins it will end up working just fine . Any suggestions? I’ve pretty much replaced and tested every component on the board.
Click to expand...
Yes, look for a zener diode or other diodes in the protection circuit. Sometimes they get leaky when they get old and will throw the DC offset.
had that problem with an A-70 amp.

You can get the service manual here:
 
Last edited:
Countdown said:
Thanks for the suggestion. Would this still be a protection issue if I swapped the amp board channels and the issue follow the amp board ?
Click to expand...
The schematics say that the amp boards are identical so, if you swapped the boards and it followed the board, then it's may not be a protection circuit issue per se. Start by checking all of the resistors on each board. Don't do anything with the power on without a Dim bulb tester! Also check all of the solder joints for rings and loose connections - use a magnifying glass.
 
You must log in or register to reply here.
Back
Top Bottom