performance teknique amp icbm 9550

[Perry Babin]

Do you have the proper supply voltages on the driver board (look at the markings near the driver board terminal pins)?

 

[Hexhclass]

on the driver board is mark 80v+ and 9+ and the other side is 80- and 9- i am getting 71v + and - and 9 v + - i am also getin 71v on the outpus to.same on the main retifers

 

[Perry Babin]

Drive the amp with a signal again and see if you read any AC on the IN pin of the driver board.

 

[Hexhclass]

i drive the amp with a signal and i did not get any AC on the driver board (in)

 

[Perry Babin]

If you measure the AC voltage from your signal source, do you see that it's producing output?

 

[Hexhclass]

well i tried two different singnal source .2v ac

 

[Perry Babin]

Is the signal present on the output terminals of the various op-amps (ICF1-ICF6)?

 

[Hexhclass]

I have not test for outputs on the op amps yet
so if there is no outputs on the op amp can that prevent the amp relay from comin on??
cause at some piont when i remove some parts from the board it use to come on whith no signal apply

 

[Perry Babin]

There may be more than one problem. If the power supply is operating but there is no audio signal at the driver board, you need to determine why. Also confirm that you have positive and negative voltage (at least ±10v) on the power supply terminals of the op-amps.

 

[Hexhclass]

i am getting 11.17v(-)and 11.79(+) on all op amp
i am also geting signal on all op amps and ther is signal on the driver board
i used a headphone speaker to test for signal

 

[Perry Babin]

Connect one speaker terminal of a woofer to the negative speaker terminal. Power up the amp and touch the other speaker wire to the bussbar (JP5) that connects the smaller cylindrical inductor to the relay. Do you have audio?

 

[Hexhclass]

yes i have audio

 

[Perry Babin]

What is the DC voltage measured directly across the diode near the end of the relay?

 

[Hexhclass]

i measure .6v dc across that diode

 

[Perry Babin]

You'll have to follow the traces from the relay/diode to see what drives it.

 

[Hexhclass]

i follow the tracks back to the power supply and found Qe3 open on the two outter leg i replace it, relay still not comin on now after the amp satys on for about 30 sec resistor Ra 11 starts to heat up fast

 

[Perry Babin]

I'm not sure how hot RA11 should get but RA10 should operate at the same temperature. As long as they're not getting so hot that they're going to desolder themselves, it's probably normal.

 

[Hexhclass]

i found the problem RA10 had increase in value it read ok on the board cause it is parallel with RA11 now amp works ok. I learn alot while working on this amp


thanks

 

[Formas]

What are the values of RA10 and RA11 (is it 2.2ohms or 3.3ohms)?

 

[Hexhclass]

Only pic i have