Rockford Fosgate Power 360a2

[seankane]

Hey Perry I have a power 360a2 that I am having trouble with. Board # PC-2065-D. It had a faulty channel putting 24 vdc to the right speaker terminal. I replaced the output fets, emitter resistors, and the gates. Still same problem. I repaired 2 Power 450S's last night with the same issue. They had SMD resistors in the channel out of tolerance. I dont seem to find any out of tolerance. The fets are puttung 24 vdc out of the drains to the terminal. Any ideas?

[Perry Babin]

It's probably not a good idea to address me directly. It may make others hesitant to help.

With the black probe on the source and the red probe on the gate of the output transistor in the defective channel. What voltage do you read for each of the outputs?

Wit the black probe on the amp's ground terminal, what is the DC voltage on the bridging terminal of the defective channel?

For both of these, polarity is important.

[seankane]

Originally Posted by Perry Babin

It's probably not a good idea to address me directly. It may make others hesitant to help.

With the black probe on the source and the red probe on the gate of the output transistor in the defective channel. What voltage do you read for each of the outputs?

Wit the black probe on the amp's ground terminal, what is the DC voltage on the bridging terminal of the defective channel?

For both of these, polarity is important.

Sorry about that Perry, kinda got into the habbit.

Q225 IRF540: 2.7 vdc
Q224 IRF9540: -.056 vdc
Q218 IRF540: 2.7 vdc
Q219 IRF9540: -.040 vdc

Bridging terminal of defective channel: -20.65 vdc

[Perry Babin]

Post the DC voltage on all of the terminals of Q211, Q222 and Q213. Place the black probe on the emitter of each and note the polarity if it's negative.

[seankane]

Originally Posted by Perry Babin

Post the DC voltage on all of the terminals of Q211, Q222 and Q213. Place the black probe on the emitter of each and note the polarity if it's negative.

Correct me if I am wrong you want the red probe measuring the terminals while the black probe is on the emitter?

Q222: 22.78 vdc
Q222: 3.427 vdc
Q222: 2.788 vdc

Q211: .518 vdc
Q211: .514 vdc
Q211: .526 vdc

Q213 I am unsure the numbers are all smeared together on the board and very hard to read I am PRETTY sure I am reading the right one.

Q213: .351 vdc
Q213: .003 vdc
Q213: .635 vdc

[Perry Babin]

You will have only 2 voltages per transistor. If you already have the black probe on the emitter of each one, the voltage (if you also place the red probe on the emitter) will be 0.000v.

[seankane]

Originally Posted by Perry Babin

You will have only 2 voltages per transistor. If you already have the black probe on the emitter of each one, the voltage (if you also place the red probe on the emitter) will be 0.000v.

Q222: 20vdc
Q222: .640 vdc

Q211: 12.61 vdc
Q211: 0.00 vdc

Q213: -.076 vdc
Q213: -.627 vdc

I think I did it right, hopefully.

[Perry Babin]

Is Q211 shorted base to emitter?

[seankane]

Originally Posted by Perry Babin

Is Q211 shorted base to emitter?

I was getting inconsistant readings, so I changed with a new 1A and now it reads 12.61vdc on 2 terminals and 0.00vdc on the other.

The amp still has the same issue.

[seankane]

Just doing some random checking and the + terminal of C215 has 36 vdc, and C115 from the other channel has 0 vdc