Rockford Fosgate Punch 75HD

[seankane]

Hello everyone.

I have a Punch 75HD with a strange issue. I recieved it for repair and it would not power on. Drew 60 amps on my power supply like it was shorted.

I replaced CR9 and CR10 and the amp powered up fine. It sat at idle for about 5 min with no issue, then all of a sudden CR9 and CR10 shorted and started smoking and it was back to drawing 60 amps on my power supply.

What could be causing this issue with CR9 and CR10? They are both IN5336B diodes. Any ideas would be great. Thanks.

 

[Perry Babin]

They are 1N5366, not 1N5336.

 

[seankane]

Yes you are correct I just made a typo. I have about 50 Punch 75hd boards in a pile some look to be ok with nothing wrong but several of them have those two diodes split and burnt.

Was this a known problem?

What causes these diodes to fail, a intermittant transformer problem??

 

[Perry Babin]

This tends to happen when the power supply becomes overloaded and the amplitude of the leakage inductance spikes increases. They're not required and can be left out.

 

[seankane]

What would cause the power supply to be over loaded at an idle? The output fets test ok, and the HBPIM was replaced. I replaced the 4 power supply fets as well.

What disadvantges are there to leaving them out?

 

[Perry Babin]

There shouldn't be spikes at low power or at idle. Do you see excessive ringing or spikes (more than a few volts) on the top of the power supply waveform?

 

[ht user]

hi to everyone,i got a punch75hd recently as a present,but when i hook up to my car,it just wont power up,check power supply everything is ok,open up and check,nothing seems burn,so,whats the cause?
thanks,