Hifonics Zeus zrx-3000.1d Help!!!
 

Hello Perry. I'm in the process of repairing a Hifonics Zues zrx3000.1d and your assistance is greatly appreciated. Thanks. When I got the amp, all 12 power mosfets, 12 gate resistors, all 4 NPN/PNP transistors along with a additional resistor by the NPN/PNP transistors were fried. So far, i've replaced all 12 power mosfets(IRFP064N), 12 gate resistors(47 ohms), all 4 NPN\PNP transistors = 2(2SC3228) & 2(2SA1275) and 1(3.3k ohm resistor). After applying power, the green power light comes and I hear the relay click. Then after about 20 seconds, the green power light shuts off and one of the 12 power mosfets overheats and fails. So, I removed all 6 power mosfets from the side that failed and applied power and the power light stays green without any of the other 6 power mosfets overheating or failing. I'm trying to figure out what is causing the problem on this side where the mosfets were removed. I checked the voltages and they all match with the working side of mosfets. Could it be the driver board possibly? If so, should I install 6 good power mosfets back in and remove the driver board to see if the problem still exits. Your help is greatly appreciated. Thanks.

do u have a scope to check the signal at the gate resistor?

Post a photo of the board. I'm not familiar with that amp.

Hello timwebb. No, I do not have a scope. Sorry.

Pictures of Hifonics Zues zrx 3000.1d
 

Here are the pictures. Thanks Perry.

Did you check the output transistors to see if any were shorted?

If you did and none were shorted, place the black probe on the negative speaker terminal and the red probe on one of the terminals of the small inductor near the green capacitor. When you power it up, do you see pulse of DC voltage there?

I will check the output transistors to see if any are short. If not, I will follow the second set of instructions and post when I'm done. Thanks.

If only one power supply fet is getting hot, I would suspect that FET of being defective or a bad connection between the Gate resistor and gate leg of that FET.

Have you tried installing all of the power supply fets in the problem side except for the one that was heating up?

Are you sure that just one was heating and not the whole bank?

Have you moved the heating fet to a different location to see if the problem follows it?

I checked the output transistors and discovered that 2 were shorted(IRF640N & IRF9640) on the same bank. I replaced them and powered it back up now the amp is only pulling .203V from my DC power supply instead of 12V. Thanks.

I will check the connection between the gate resistor & gate leg of the FET that is heating up. I will also remove the FET from the circuit and see what happens. Thanks.