Rockford Fosgate T20001bd

[Perry Babin]

Solder a bridge across R315.

What do you see on pin 7 of U301 and U302?

 

[caraudioguy2100]

After soldering a bridge across R315 this is what I get on pin 7 of both ic’s scope set to .2ms .2volts/div

 

[Perry Babin]

Set the timebase to 10us.

Is the probe on 1x or 10x?

 

[caraudioguy2100]

Probe is set to 10x

here is what I get when set to 10us

 

[Perry Babin]

What do you see on the gates of the rail switching FETs?

 

[caraudioguy2100]

On the outputs I get the following 2 signals on the gates scope set to 10us 2volts Div .

 

[Perry Babin]

What's the DC voltage on pin 3 of the 3706 driver ICs?

 

[caraudioguy2100]

5.44 on both

 

[Perry Babin]

Which pins of those ICs do you see a square wave?

 

[caraudioguy2100]

Pin 1,6,11,16 on U400

Pin 1,16 on U401

 

[Perry Babin]

Do you still have signal on pin 7 of U301?

 

[caraudioguy2100]

Pin 7 of 301 I get a square wave

 

[Perry Babin]

Re-check pins 2, 6 and 11 on U401.

 

[caraudioguy2100]

I do not get a square wave on pins 2,6,11 of U401

 

[Perry Babin]

What about pin 2 of U400?

 

[caraudioguy2100]

No

 

[Perry Babin]

On resistors R309 and R322, do you have a square wave on one end but nothing on the other end?

 

[caraudioguy2100]

I do not get square waves on either one of them both sides have no square wave

 

[Perry Babin]

Didn't you have a square wave on pin 7 of both U301 and U302?

 

[caraudioguy2100]

I had a square wave but now it’s gone