Rockford Punch 800a2

[seankane]

You need to determine why you don't have negative 15v on pin 4 of the op-amps. Check the LM337.

I replaced lm 339 with no difference still have 4.5 vdc on all of the op-amps pin 4's and full rail voltage on speaker terminal, R206 and R306 have 4.5 vdc as well just not sure where to go next. I seem to be better at major repairs than little stuff like this. Any suggestions?

 

[Perry Babin]

The LM337 is the negative regulator.

 

[seankane]

I dont see any LM337 The only ones on the board are LM339, TL072C, and LM833. Is the LM833 the negative voltage regulator?

 

[Perry Babin]

It's clamped to the heatsink.

 

[seankane]

AAHHH gotcha Perry just like the one that was bad in that BD1500. Ok I will check its output and get back to you. Thank you I feel dumb I totally forgot about it being soldered to the mesha board was looking on the board for it.

 

[seankane]

The LM337 has - 55 vdc on the center leg and + 4.50 vdc on the outside 2 legs. This seems defective or overloaded?

 

[seankane]

Perry replaced both LM337 and LM317 and the rail voltage is gone on the terminals. That would explain why I had + rail voltage on one side and - rail voltage on the other side. Both were burnt black inside upon popping them apart. What would cause both of these to go out. Someone reversing polarity on power supply? I am going to test for sound now................TTYS

 

[Perry Babin]

That could explain the rail voltage on the speaker terminals.

I don't know what would cause them to fail. Reversing the B+ and ground would not have done it.

 

[seankane]

Perry amp sounds amazing, thanks again for everything, you are an amazingly smart person. I hope someday to be as good as you are. The amp is rocking on the bench and sounds great..............