DS18 spl12.5K

I have a DS18 spl12.5K, this unit has 32 mosfets (4 banks of 24N50) for output fets. With all mosfets removed, I measure the impedance from gate to source on the board, 3 banks read 10K ohm,however 1 bank reads 25K.
Is this a problem?
 
output board

Yes, power supply is working. I have replaced all transistors and Ic's on drive board and removed all output fets
 

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good rail voltage

Both rail voltages are present. I have a square wave signal on all gate inputs hi side and low side.
Should I be seeing oscillation on hi side gate? Can't get a picture of back side of drive board without removing it.
 
The fan is held in with a couple of screws.

On amps that use a diode on the driver board to supply the high-side B+, you can apply voltage to the high-side with a 9v battery. I'm not sure if that works on the ZNCM boards.

Does the positive high-side supply terminal on the 21844s connect to the corresponding NPN buffer/driver transistors that drive the high-side FETs?
 
fixed

Found the problem!!
Open resistor R51 (circles in red) 1 ohm.

No signs of getting hot or burnt in any way.
Probable the component that failed and caused all the other problems.
Thanks for the help
 

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