hi guys
long time reader, first post
i have my dad's pioneer amp and it has started to drop out when using it at any volume level.
it has been matched to the same pair of speakers for 20+ years
you can hear the power relay click on and off when it does this. jiggling the power switch does not influence the problem in any way.
im wondering if anyone has come across a similar problem and can point me in the right direction to start looking at fixing this?
thanks in advance!
long time reader, first post
i have my dad's pioneer amp and it has started to drop out when using it at any volume level.
it has been matched to the same pair of speakers for 20+ years
you can hear the power relay click on and off when it does this. jiggling the power switch does not influence the problem in any way.
im wondering if anyone has come across a similar problem and can point me in the right direction to start looking at fixing this?
thanks in advance!
amptech .... in a way this the number one wrong approach ( refering to the big caps )
if for example one amplifier has leacky or dry filter capacitors will work perfectly allright until you ask ammounts of power from it .If 5% of the out is only needed will work like charm even with dry capacitors....
on the other side one amplifier with a dry capacitor in the signal/feedback chain will not play at all or like the OP above will have problems starting up if aux power supply that feeds protection and preamp circuits is under some kind of fault
protection circuits feature also caps in the signal path that also might be a reason fro not starting up properly
main filter caps might be a problem after all these years but will not effect the operation of the amp in low or very low power ...that puts the filter caps by far lower to the fault trace chain ...
kind regards sakis
if for example one amplifier has leacky or dry filter capacitors will work perfectly allright until you ask ammounts of power from it .If 5% of the out is only needed will work like charm even with dry capacitors....
on the other side one amplifier with a dry capacitor in the signal/feedback chain will not play at all or like the OP above will have problems starting up if aux power supply that feeds protection and preamp circuits is under some kind of fault
protection circuits feature also caps in the signal path that also might be a reason fro not starting up properly
main filter caps might be a problem after all these years but will not effect the operation of the amp in low or very low power ...that puts the filter caps by far lower to the fault trace chain ...
kind regards sakis
hi everybody, thanks for the informative replies.
it sounds like a good idea for me to check the soldering along the power supply and protection circuits.
something worth noting - once a week when you power the amp up it will make a bzzzzzz sound for 1 sec then power up. it sounds similar to when the amp drops out for a second...
it sounds like a good idea for me to check the soldering along the power supply and protection circuits.
something worth noting - once a week when you power the amp up it will make a bzzzzzz sound for 1 sec then power up. it sounds similar to when the amp drops out for a second...
Forget about capacitors for now.
Inspect throughout and resolder as required.
Look for small temperature monitor transistors in thermal contact with the main heatsinks and be sure to resolder these (if present).
If this does not cure the fault small electros in the protection stage may be the culprit.
Eric.
Inspect throughout and resolder as required.
Look for small temperature monitor transistors in thermal contact with the main heatsinks and be sure to resolder these (if present).
If this does not cure the fault small electros in the protection stage may be the culprit.
Eric.
Is your silver pioneer have it's blue led display to the left side or in the middle?
you say it drop's 'out' at any level...is there any distortion or is the music level coming out the speaker side weak?..
we need to know how things sound to speed the repair up, retry powering up with out speaker loads connected..
you say it drop's 'out' at any level...is there any distortion or is the music level coming out the speaker side weak?..
we need to know how things sound to speed the repair up, retry powering up with out speaker loads connected..
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