Alpine MRD-M300

[mike49504]

I got this amp in for repair it appears to power up but i get no voltage on the gate leg of the power supply fets..

Heres what i have on the 494

Pin 1:0.22
Pin 2:4.33
Pin 3:0.08
Pin 4:5.03
Pin 5:1.71
Pin 6:3.49
Pin 7:0
Pin 8:13.86
Pin 9:0
Pin 10:0
Pin 11:13.86
Pin 12:13.86
Pin 13:5.05
Pin 14:5.05
Pin 15:5.05
Pin 16:0

 

[Perry Babin]

Pin 4 is being driven high but I don't have the service manual so I can't offer any suggestions. Many times a shorted or leaking output will cause it to go into protect so check those carefully.