Pioneer SX-780 Voltage Regulator Trouble

[CaseyWKC]

Go ahead and remove Q6, they don't normally run hot. That should bring things back to working except for FM.

@mrk229 and @tarior

Removed Q6 this morning, fired her up and tape mon switches lit up first thing, relay pulled in, all worked but FM.

I pulled the PA1001 from what I think is a parts 580 I had laying around, threw it in and all is well!

FM pulling in stereo and every function working like it should.

This is definitely a first for me as well. The wet finger heat test made things really apparent in this instance!

Thank you guys for all of your help! Maybe this thread will serve to help somebody in the future if they run into the same issue!

 

[mrk229]

@mrk229 and @tarior

Removed Q6 this morning, fired her up and tape mon switches lit up first thing, relay pulled in, all worked but AM.

I pulled the PA1001 from what I think is a parts 580 I had laying around, threw it in and all is well!

FM pulling in stereo and every function working like it should.

This is definitely a first for me as well. The wet finger heat test made things really apparent in this instance!

Thank you guys for all of your help! Maybe this thread will serve to help somebody in the future if they run into the same issue!

It is indeed a bit of an odd one. I learned that a not very stiff zener reference voltage is fairly easily pulled down.

I think if the 13 volt power supply did not sag like that you would have easily found the problem when the smoke rolled forth.

Thanks @tarior for the 2SK34 explanation.

 

[tarior]

@mrk229 and @tarior

Removed Q6 this morning, fired her up and tape mon switches lit up first thing, relay pulled in, all worked but FM.

I pulled the PA1001 from what I think is a parts 580 I had laying around, threw it in and all is well!

FM pulling in stereo and every function working like it should.

This is definitely a first for me as well. The wet finger heat test made things really apparent in this instance!

Thank you guys for all of your help! Maybe this thread will serve to help somebody in the future if they run into the same issue!

Nice job. You have to use all of your senses when sorting these things out. Sometimes just touching a component will tell the tale.