Rockford Fosgate T30001BD

[mike49504]

Ok now i did this right

Q8:0.60

Q11:1.31

Q12: shorted. Its marked G1 or 61 Do you have a part number for that?

 

[Perry Babin]

MMBT5551LT1

With the black probe on the ground terminal of the amp, what's the DC voltage on the point where R13 and R53 connect?

What's the DC voltage where R66 and R69 connect?

 

[mike49504]

Where R13 And R53 connect:3.73 volts

Where R66 And R69 connect: 4.81 volts

 

[Perry Babin]

Do you have two multimeters? If so, measure both at the same time. This supply is floating and you may not be getting reliable readings.

 

[mike49504]

Ill have to get another one in the morning

 

[Perry Babin]

Don't go buy another one just for this.

 

[PQatPIT]

How is this progressing? I have one T40001bd here with similar problems.

 

[mike49504]

So far i found 1 of the a56's on the board shorted . If all the power supply fets check ok none shorted check the A56's and A06's on the board (behind power connections) to start with

 

[PQatPIT]

No shorted transistors here. If I lift red and blue wires out and power amp up then the voltage is +4V at red, and +200 or so on blue. This can't be right?

I disassembled both boards out and I see no broken pcb traces or anything like that to be defective.

 

[Perry Babin]

The rail voltage for these amps isn't like other amps. The output of the power supply is floating so, under normal operation, the red wire will swing from 0v to full rail voltage. The blue does the same. If you reconnect the wires, what voltage do you read on those two wires?

Check it with the black probe on ground as well as measuring directly across the red and blue wires.

 

[mike49504]

Perry,

On the one im working on Im thinking i have a shorted transformer.
The bottom side of 1 of the transformers is black like it was smoking at one time. All the amp does when i try to power it up is make a loud squealing sound and go right into thermal

 

[Perry Babin]

It's VERY rare for a Rockford transformer to fail but if it has, a replacement should be available from pacparts.