MTX Thunder 6500D does not power up

[tidom78]

Hi,

I blew my amp last week. (short circuit on the output speaker )

I see that the four 75339P were smoke. I changed all four with IRF3205 and now the amp doesn't want to turn on.

Did someone have an idea if I have something else blew?

Thanks,

 

[Perry Babin]

Post a list of the DC voltage on each of the 16 pins of the TL494.

 

[tidom78]

Here's the DC voltage of the TL494

PIN #1 : 0
PIN #2 : 0
PIN #3 : 0.06v
PIN #4 : 1.15v
PIN #5 : 0
PIN #6 : 0
PIN #7 : 0
PIN #8 : 11.5v
PIN #9 : 0
PIN #10 : 0
PIN #11 : 11.5v
PIN #12 : 11.6v
PIN #13 : 5v
PIN #14 : 5v
PIN #15 : 5v
PIN #16 : 0

The LED that show the power on wasn't on!🙁

 

[Perry Babin]

The IC has input power on the right pins but 5 and 6 should not be near 0v. Pin 6 should be ~3.7v and pin 5 should be ~1.5v. If those are accurate readings and nothing is shorting those pins to ground, the IC looks like it's damaged. In most cases, when the IC is damaged the 5v reg is off but yours is dead on.

With no power appled to the amp, set your meter to ohms and measure the resistance between pins 7 and 6 and then between 7 and 5.

 

[tidom78]

Between the pins 7 and 6 is 1.8 kohm
And between pins 7 and 5 there is infinite.

 

[Perry Babin]

I think the IC has failed.