Rockford Fosgate p10002 Mosfet Cross Reference Help

[2012stankiewicz]

Hey guys!!! Have a cross reference problem here with my p10002 power mosfets. Everything is working except 1 channel has a low power output to the subwoofer. I am running a 2 ohm load per channel with 12" Alpine type R's. I have included pictures of the problem area and all FET numbers according to the board numbers, starting with:

Q17 and Q14 - 337T - not working. believe I found the correct part.
Q16 and Q13 - 317T - appears to be fine.
D11 - part number CQ543 -I cannot cross reference to anything.
D12 - part number CQ614 - " "

Any ideas of what alternate part number goes in D11 and D12? Or where can I find these numbers? How do I freshen up the area?

 

[brandes.cm]

Q17 and Q14 - 337T - not working. believe I found the correct part.
Q16 and Q13 - 317T - appears to be fine.
D11 - part number CQ543 -I cannot cross reference to anything.
D12 - part number CQ614 - " "

LM337t and LM317t are adjustable voltage regulators, rarely do they fail. D11 and D12 are rectifiers and again those rarely fail.

Do you have +- rail voltage, op-amps have +- supplies working?

 

[Perry Babin]

I agree, these parts rarely fail.

Unless you have experience replacing the parts on the MEHSA insulators, you should not attempt to replace them unless you know them to be defective.

None of the parts you listed are FETs (MOSFETs).

Why do you think the regulators are defective?

The numbers that you're using for the rectifiers are not the part numbers. D11 is an MUR1620CT. D12 is an MUR1620CTR.

 

[2012stankiewicz]

i ran my volt meter over them as i seen in previous forems and i get OL on just one of the rectifiers. is this the proper way to test these? all other mosfets are good as far as my meter says. OL on all. i just have very week sound from one side and good sound on the other.
what else could it be? any guidence is greatly appreciated.
thanks for the fast response!
thanks,Dan

 

[Perry Babin]

Have you tried operating all of the pots and switches through their entire range to see if it made a difference in the weak channel?

Have you swapped the RCAs (L-R)?

Have you swapped the speakers (L-R)?

 

[2012stankiewicz]

yes, i swapped the RCAs and swapped the sub and its all the same. weak power on one side. i just went through the rectifiers as i seen in the basic car amp repair. and i dont get any that are "open" i get like .200 2.01 etc. i got one that has OL. are these NPN or N Channel. just want to make sure that im testing the right way.
im new to this i have done alot of small stuff on boards and never got this deep into it.i have replaced FET's before' and had good luck even getting them off the MEHSA board and back on again.
thanks again guys!!

 

[2012stankiewicz]

i have checked the other FETs and i get 3 that have OL and the rest are all out of wack with numbers all over the place.. could that be my problem? just blown channel FETs? and my rectifiers are good?

 

[Perry Babin]

The rectifiers are not NPN (a type of bipolar transistor) or N-channel (a type of field effect transistor).

Is the weak channel distorted or is it producing clean audio at a reduced level?

 

[2012stankiewicz]

I'm still studying guys. Sorry to leave ya hanging. Kids,wife,life....
I really wanna learn so I'm reading alot, so I don't have stupid Knowlege-questions!
I'm going to order Perry's guide. I have to learn alot I guess. I will be getting back when I think im ready to do surgery. I have done a few things on small amps not this big.
So if you guys would just hold on to this thread, much appreciated!!

Gotta go study like collage for this stuff, I'm down!!!!
Thanks, Dan!!!

 

[2012stankiewicz]

Oh clear sound on the bad channel. Very clear very low.

 

[Perry Babin]

If you don't have a test tone/sine wave signal source, download THIS and play it through the amp.

Check the signal at the output (pins 1 and 7) of each op-amp in the circuit for each channel to see where the signal becomes weak. If you don't have the schematic diagram, email me. I have the one for the 1405-51346 board.