ATG 6500.1D (the other amp)

[caraudioguy2100]

This is amp number 2

This one doesn’t power up

Here is what I get on the 3525

Pin 1:0.00
Pin 2:5.01
Pin 3:0.00
Pin 4:0.14
Pin 5:2.09
Pin 6:3.60
Pin 7:2.07
Pin 8:0.29
Pin 9:5.47
Pin 10:0.00
Pin 11:0.00
Pin 12:0.00
Pin 13:13.47
Pin 14:0:00
Pin 15:13.47
Pin 16:5.01

 

[Perry Babin]

8, 11 and 12 are missing 12v.

 

[caraudioguy2100]

Pin 8,11,12 are supposed to have 13 volts on the SG3525 I thought it was pins 13 and 15

 

[AllenB]

Thread split

 

[Perry Babin]

Pin 8 isn't charging the SS cap. Remove the cap to see if it will go to about 5v.

 

[caraudioguy2100]

I removed C57 directly connected to pin 8 and no change

 

[Perry Babin]

If pin 10 is 0v, the IC looks to be defective.

 

[caraudioguy2100]

Replaced the ic amp shows some life now .

The amp is stuck in protection mode .

I removed the audio driverboard and the outputs .

On 1 bank of outputs it still shows a short from drain to source on the pads for the outputs .

 

[Perry Babin]

Post the DC voltage on all terminals of the comparator adjacent to the 3525.

 

[caraudioguy2100]

Lm393

Pin 1:0.00
Pin 2:2.52
Pin 3:0.00
Pin 4:0.00
Pin 5:0.00
Pin 6:2.52
Pin 7:0.00
Pin 8:5.09

Something is shutting the amp down since I only get 0.29 volts on pin 8 of the 3525 with a new ic and pin 10 is still at 0 volts if I remove the rectifiers the amp will power up

 

[Perry Babin]

Do the voltages posted change without the rectifiers?

Is the voltage actually 0.00v on all of those pins?

 

[caraudioguy2100]

Voltage on the LM393

With rectifiers in the amp

Pin 1:0.00
Pin 2:2.52
Pin 3:0.00
Pin 4:0.00
Pin 5:0.19
Pin 6:2.52
Pin 7:0.00
Pin 8:5.05

With rectifiers out of amp

Pin 1:4.99
Pin 2:2.52
Pin 3:4.34
Pin 4:0.00
Pin 5:4.98
Pin 6:2.52
Pin 7:3.87
Pin 8:5.05

 

[Perry Babin]

Is terminal 3 or 4 of IC303 connected to any terminal of the driver board?

If so, which to which?

 

[caraudioguy2100]

Which one is IC303 ?

 

[Perry Babin]

I was using the photos of a similar amp that were better quality. I think it's IC4 in your photo.

 

[caraudioguy2100]

Terminal 3 connects to pins 5,10 of the audio driver board

Terminal 4 connects to pin 9 of the audio driver board

 

[Perry Babin]

It appears that the pin configuration is different than similar amps.

5 and 10 should be the secondary ground.

Pin 9 is the control terminal.

When the rectifiers are in the amp and it shuts down, do you have 12v on both terminals 13 and 15 of the 3525?

 

[caraudioguy2100]

With the rectifiers in circuit

Pin 1:0.00
Pin 2:5.05
Pin 3:0.00
Pin 4:0.14
Pin 5:2.06
Pin 6:3.66
Pin 7:2.05
Pin 8:0.30
Pin 9:5.55
Pin 10:0.00
Pin 11:0.00
Pin 12:0.00
Pin 13:13.47
Pin 14:0.00
Pin 15:13.47
Pin 16:5.05

 

[Perry Babin]

Is the 3525 in a socket?

 

[caraudioguy2100]

No