kicker kx1200.1 no audio out

[Nutcase21]

i did check them, the 4 1661's and 4 4373's all tested good.

 

[PapaZBill]

Perry, I suppose it's possible, not exactly sure how. We can try an equipment.

First recheck with an ohmmeter L102,L104,R157,R217,R192,R202,R155,R215

Remove D106,D119-LL4148 and check with an ohmmeter/diode checker. reinstall or replace if necessary.

Check DC voltages around Q113,Q135,Q121,Q122,Q123

Remove D110.D117-LL4148's and check with an ohmmeter/diode checker. They are the sense diodes to over current protection circuit for the neg drive.

With diodes removed power the amp and check for drive.

If you have the KTA1661y's and the KTC4373y's you may want to replace them all. Is It possible the A1381's are damaged?

 

[Perry Babin]

The B-E voltage on the standing drivers should give an indication as to whether the B-E junction is reverse biased by the protection circuit.

 

[PapaZBill]

Thanks Perry, I believe you may have put your finger on it. Checking voltages around the A1381 should tell us something.

Pay particular attention around Q122. There should be zero volts DC on the base and emitter and 12 volts on the collector (center lead or tab). If the voltage on the base is high it will cause both A1381's to be reversed bias and shut down the drive for the IRF640's.

 

[Nutcase21]

voltage on the Q122 collector is -12.1 and 0 on the base and emitter.

 

[PapaZBill]

Check DC voltages around Q104,Q126,Q113,Q135,Q121,Q122,Q123 and post.

This will give us a better overall picture of what is happening with this amp.

The voltages around Q122 looks good. Recheck R192 & R202 also.

The more information I get the better able I can advice. Read through all of mine and Perry's post and post all requested measurements even if you think they may be irrelevant.