Directed D2400

[S Merlington]

This amp had blown outputs and a couple of drivers that were bad ..

I removed all of the outputs and also removed the driverboard..

The 3 board locations marked in red is were the 9640's go ..

It says i have 0.6 ohms between pads 1 and 2 on the main board even with the driverboard and all outputs removed..

I checked for solder bridges but found non..

The other side were the 9640's sit say i have 62 ohms between pads 1 and 2..

Any ideas what can cuase this ?

 

[amc32]

Check for shorted zeners

 

[S Merlington]

Ok i solved that problem..

Next problem i have is the amp is stuck in protection mode ..

Heres what i have on the 494

Pin 1😛ulses between 3.88 and 4.02
Pin 2:3.97
Pin 3:4.92
Pin 4:0.17
Pin 5:1.56
Pin 6:3.73
Pin 7:0
Pin 8:13.88
Pin 9😛ulsing between 0.12 and 0.43
Pin 10:0
Pin 11:13.90
Pin 12:13.58
Pin 13:5.07
Pin 14:5.07
Pin 15:5.07
Pin 16:0

 

[Perry Babin]

The shutdown of the power supply could be due to either pin 1 or 3 being driven high. What's connected to pin 1 and pin 3?

 

[S Merlington]

Pin 1 connects to a C3198 transistor

 

[Perry Babin]

What leg does it connect to?

What is the voltage on all 3legs of the c3198?

 

[S Merlington]

I replaced the C3198 now the amp powers up fine..

Im going to stick the rectifiers back in and see if i can get it to power up and produce audio