Rockford Fosgate p1000-1BD.

[rhempz01]

I have the punch that has completely obliverated the power supply and 2 shorted output transistors. I have drive still on all the ps gate signal. My question is does this amp have 16ohm gates in q1004, Q1003, and Q100? Are they the same fet 75344G?. Q1000, Q1002, Q1005 have the normal 60.5ohm. the outputs are IRFP260N. I can't believe the drivers survived or ic. They complete burnt the mosfets off the pads.

 

[KyferEz]

Did none of the gate resistors survive? Typically at least one will and you can measure that after taking it off the board. They go up in resistance when they go bad and often will break when taking them off if bad.

 

[rhempz01]

Yes all survived the bank in the back of the amp all measure 16ohm and the bank on the side measure 60.5ohm. I'm thinking this normal for this amp. The drive even survived. Only the rear 3 look slightly strange.

 

[KyferEz]

Can you see the markings on them? If so post them.

 

[Perry Babin]

Did you check them before or after removing the blown FETs?

 

[rhempz01]

both perry, I checked them i thought they were just out, until they all tested exactly 16 ohm. I thought they would all be 60ohm but the marking are slightlly visable now cleaned. Ill see if i can make out anything from the markings.

 

[Perry Babin]

They are 47.5 ohms. With shorted FETs in the board, all would essentially be connected in parallel and give a reading 1/3 of the actual value.

 

[rhempz01]

Ok so the fets came in today. I need to change a few gate resistors. Where are the drivers for the outputs?

 

[seankane]

The large A56 and A06 transistors. 3 in each channel, I believe one is used for a regulator in each channel.

 

[rhempz01]

What goes bad on the driver boards of these amps how sensitive is the uc3526adw.? I installed new ps mosfets and it draws current and the gate drive is way off

 

[Perry Babin]

The drivers may have failed. The 3526 doesn't fail often.

Q100-Q103 are the drivers if you have the 52783 driver board.

IF you have chipquik, use it if you have to remove the driver board.

 

[rhempz01]

That is in fact the driver board perry. Removed with ease with quick chip. Glad I took your advise there. All the via look great. I didn't think that chip failed often. The amp burnt the power supply up badly.

 

[Perry Babin]

Be sure to remove as much as possible of the CQ from the header and board before reinstalling it.

 

[rhempz01]

Gate drive looks good now. I used my soder wick to remove what was remaining on the pads and riser legs.

 

[rhempz01]

I should be using irf064n in the power supply correct? Or the 75344G?

 

[seankane]

Either will work, if you use IRFP064N use 47 ohm gate resistors.


Using the 75344G keep gates as they were OEM.

 

[rhempz01]

So I went with Irfp064n in the power supply and changed all the gate resistors to 47ohm. Powers up great, nice and cool. So my question, this amp runs the Irf260N in output section oem? Or did someone use them, Is that what I should use in it?

 

[seankane]

I believe those are OEM.

 

[rhempz01]

Ok I got them from mouser. Just making sure. The ps burnt up so bad and only two of the output failed. Since it has a all new ps, it will have all new fets in the output stage as well. I can see the drive signal when I probe the output drive board and a triangle wave on one pin. But not at output transistor locations.

 

[Perry Babin]

If you have the 52874 driver board, try jumping the points shown. Use very small, flexible wire and not too much heat.