Need help. Esx signum se7000d

[Vytautas1]

I need help identifying ic's on driver board

 

[Vytautas1]

My guess is that the scrached chips are these IR21844s and lm211. Is it right?

 

[MarioRestucci]

Yep.

 

[Vytautas1]

Thanks. In this amp mosfet 38n30 is discontinued. Can i use FDA59N30?

 

[Perry Babin]

FDA38N30 ON Semiconductor - MOSFETs - Distributors, Price Comparison, and Datasheets | Octopart component search

 

[Vytautas1]

My mistake. So fda and fqa are the same?

 

[Perry Babin]

For the limited FQA parts that I've used, they have been. That's not definitive. Look at the specs. In some instances, a change in the part number prefix or suffix has nothing to do with the semiconductor itself. It could be a minor change in the package.

 

[Vytautas1]

Specs is slightly different, but it should work

 

[Vytautas1]

So i changed all mosfets, two driver chips ant one 27ohm resistor. Amp works, but have one issue - the relay turns on before the amplifier starts operating (0.5 sec.). I dont know if its bad or not.

 

[Vytautas1]

I took some time

 

[Perry Babin]

How do you define 'starts operating'?

 

[Vytautas1]

Class d switching signals appears after relay turns on.

 

[Perry Babin]

Some of these self-oscillating amps won't oscillate until there is a signal. Have you tried driving a signal into the amp to see if the rail-rail switching starts earlier?

It shouldn't start until the rail voltage has reached maximum voltage. If that's as it should be, maybe the delay for the relay is too short.

 

[Vytautas1]

I dont tried with signal. Looks like relay turns on to early. Today i put amp in the car and plays fine. I almost blown my sub 😅