Jl audio 1000/1

[megael9]

Hi guys:
I'm working this amp and can just not
Get to understand it. The power and
low ohm light are both on. I noticed that
The power supply MOSFETS have about
47 ohms from gate to ground, and when
Measure from the signal side of the MOSFET
Resistors there's 0 ohms. The pwm signal is
shorted to ground. Pulled out the pwm
Board and still there's a short. Any
suggestion.
Thanks in advance

 

[blazer40]

Sounds like a full rebuild of at least the power supply and maybe more.

 

[megael9]

This amp have 24 power supply MOSFETS
12 pairs, one of every pair is measuring zero
Ohms from the gate resistor to ground, it's
This normal for this amp. I pulled out all the
Gate resistor and still zero ohms to ground.
Can some one with an amp like this try to
measure this and let me know?

 

[evianamp2011]

Just a guess, but its probably measuring zero because of the filter caps (they are parallel to the B+ and ground input) causing it to look like a short.

 

[Randy62]

Gate drive transistors are shorted.