PC21400.2 power supply failure

[Bmwe21]

The power supply on my pc21400.2 has failed and i bought all new power supply transistors rfp70n06, u820 diodes, new 22 ohm gate resistors, sg3524n pwm and hip4081aip transistor drivers. So with all of the power supply transistors out i do not have a drive signal on the gate. Im not familiar with how this driver circuit works. Any one have some info on what i should check?

Thanks shawn

 

[Perry Babin]

Do you have output from the 3525 to the inputs of the HIP4081 ICs?

 

[Bmwe21]

What should i see as a out put? Should the out put look like a tl494 out put?
Pin
1. 0
2. 2.79
3 .820
4 2.0
5 4.84
6 4.18
7 4.83
8 .712
9 0
10 0
11 0
12 0
13 12.7
14 10.4
15 12.7
16 5.6

Somthing seems rong to me.

 

[Bmwe21]

Thats the pinout of the sg3524n with the amp powered up. With no transistors on the power supply.

 

[Perry Babin]

Is the installed IC a 3525 or a 3524?

 

[Bmwe21]

3524n

 

[Perry Babin]

All similar amps use a 3525, not the 3524.

 

[Bmwe21]

That could be the issue. I bought the amp not working and someone had been trying to repair it. So i would not be surprised that rong parts were installed. Thanks for the info!

 

[Bmwe21]

I have some new sg3525a and i will try that out tonight.
Thanks!