Rockford fosgate 201s will not power on.
Any guys here anymore? There used to be a wealth of knowledge, but i have not been here for quite a few years.
Trying to diagnose a non functioning amp.
Input power is 12.95v
Tl494 voltage is as follows.
1. 0.00
2. 4.41
3. .06
4. 0.00
5. 1.46
6. 3.26
7. 0.00
8. 12.20
9. 7.46
10. 7.29
11. 12.20
12. 12.20
13. 4.83
14. 4.83
15. 4.83
16. 0.00
Gate and drain of both power fet's are both 12.92
Resistors look to be in spec.
Its been a lot of years since i have done this so thats about all i know to check.
I do have the schematic and most the parts to change anything, and the skills to do smd.
Anyone with guidance?
Any guys here anymore? There used to be a wealth of knowledge, but i have not been here for quite a few years.
Trying to diagnose a non functioning amp.
Input power is 12.95v
Tl494 voltage is as follows.
1. 0.00
2. 4.41
3. .06
4. 0.00
5. 1.46
6. 3.26
7. 0.00
8. 12.20
9. 7.46
10. 7.29
11. 12.20
12. 12.20
13. 4.83
14. 4.83
15. 4.83
16. 0.00
Gate and drain of both power fet's are both 12.92
Resistors look to be in spec.
Its been a lot of years since i have done this so thats about all i know to check.
I do have the schematic and most the parts to change anything, and the skills to do smd.
Anyone with guidance?
Last edited:
Gate and Drain should not be both 12.95vdc.
The gate should be around 5vdc.
What reading do you get from gate to source with your meter set to ohms. Make sure to use auto range.
The supply FET's could be shorted.
The gate should be around 5vdc.
What reading do you get from gate to source with your meter set to ohms. Make sure to use auto range.
The supply FET's could be shorted.
Dead short gate to drain. The gate resistors are burnt also.
Anything else i need to check or replace? Got a pile of parts for it. Repaired an old 1000a2 a bunch of years ago and ordered a bunch of extra parts.
Anything else i need to check or replace? Got a pile of parts for it. Repaired an old 1000a2 a bunch of years ago and ordered a bunch of extra parts.
Do you have any shorted outputs? IRF540/IRF9540
Measure from gate to source with your meter. If you find a shorted one or more clip the legs and then power up the amp.
If there is shorted outputs, check the gate resistors and source resistors for the outputs.
If any of the outputs are shorted it will cause what your experiencing. If you have any open source resistors you will likely have protection circuit damage as well.
Measure from gate to source with your meter. If you find a shorted one or more clip the legs and then power up the amp.
If there is shorted outputs, check the gate resistors and source resistors for the outputs.
If any of the outputs are shorted it will cause what your experiencing. If you have any open source resistors you will likely have protection circuit damage as well.
That was it. One side outputs were shorted. Clipped them and it fires up.
I have forgotten most of what i learned before. I got a few amps to tinker with now. Maybe it will be enough to retain some.
Thanks for the help.
I have forgotten most of what i learned before. I got a few amps to tinker with now. Maybe it will be enough to retain some.
Thanks for the help.
Of course, the one part i don't have. Irf540 and irf9540
Got a pile of 640 and 9640, guess i need to order parts.
Got a pile of 640 and 9640, guess i need to order parts.
Also when ordering new outputs for the amp order the non N version
The IRF540N and IRF9540N will not work in this amp.
Order the IRF540 and 9540 and like he said also check the source resistors to see if any are bad before placing a parts order it will save you time
The IRF540N and IRF9540N will not work in this amp.
Order the IRF540 and 9540 and like he said also check the source resistors to see if any are bad before placing a parts order it will save you time
What is the difference? Been trying to find somewhere that explains all the part numbers but no useful info so far.
Not sure without looking at the data sheet.
I have used them in repairs using 540N and 9540N and had no problems.
I have seen problems with using 540N and 9540.
I would get the non "N" versions of both. Order from Mouser, Arrow, or other reputable distributors.
I have used them in repairs using 540N and 9540N and had no problems.
I have seen problems with using 540N and 9540.
I would get the non "N" versions of both. Order from Mouser, Arrow, or other reputable distributors.
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