Help with PPI PC 21400.2

[integrite07]

Hey if anyone is out that can give me the values of R172 and R79 would be very helpful. I just got this amp in for repair and the southside part of the power supply all the fets were shorted a couple were blown, along with half of the gate resistors and also the resistors that i stated above. Any help would be great

Thank you

[Perry Babin]

Can you post a photo of the board showing the location of the resistors?

[integrite07]

yes here it is one of my employees replaced them with what he thought was right but i dont want to power it up and them be wrong.

[Perry Babin]

The closest thing I have photos of is a 2350. In the 2350, R79 is definitely 10 ohms. I think R172 is probably also 10 ohms. If it connects to the mylar cap in the same way, it's almost certainly 10 ohms.

[integrite07]

Great thanks for the help. I replaced those and it powered up then all i could hear was a small click turns out it shorted out some power transistors they are shorted out in an alternating order should i replace the pwm and the other two ic's

[Perry Babin]

The HIP4081s typically fail when the FETs fail so you'll likely need to replace those.

They're shorted in an alternating pattern because the banks are interlaced. In this amp there are 4 banks of FETs.

If you find the FETs that read less than ~40 ohms between the gate and the other legs of any individual transistor, you can remove those from the circuit an determine if the drive circuit has been damaged also.

[integrite07]

Your such a huge helP and reply so fast thank you I will get everything ordered and replaced and I will let you know after. Thanks again perry you're always helpful