Sony XM-GS400

Here's the first pic
 

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If this amp has a normal power supply, pin 10 should cause about the same voltage to appear on the gates of the FETs (if the drive circuit isn't damaged). That should drive 1/2 of the FETs fully on, causing the amp to draw excessive current.

If leg 1 of the PS FETs is near 12v, leg 3 is at ground and the center leg is near B+ voltage, the FETs are blown.
 
I removed all of he power supply fets and tested them
They test fine in and out of the board ..

After removing them from the amp I get the following voltages on the pads for the power supply fets

Gate:4.97
Drain:13.88
Source:0.00

On the 594 I get

Pin 1:0.00
Pin 2:2.51
Pin 3:0.05
Pin 4:0.33
Pin 5:1.44
Pin 6:3.73
Pin 7:0.00
Pin 8:13.89
Pin 9:5.86
Pin 10:12.99
Pin 11:13.89
Pin 12:13.89
Pin 13:4.98
Pin 14:4.98
Pin 15:4.98
Pin 16:0.01

Could this IC possibly be defective?