Kicker cxa300.1 ic3 identification.

[rhempz01]

I need to know what ic3 is. Its burnt so i cany make out the print.

 

[rhempz01]

Pic2

 

[PapaZBill]

IC3 is an MP18021 gate driver. R105 will be open also.

 

[PapaZBill]

IC3 is an MP18021 gate driver. R105 will be open also.

R105 is a 4.7 ohm. Check to be sure there are no shorted outputs-AOT412's and filter Capacitors-2200uF/50v.

If nothing else, before replacing the AOT460's and after replacing the 18021 and R105, remove R68-4.7k ohm and check the Drive to the Gate resistors.

If all looks good replace mosfets and you should be good to go!

 

[rhempz01]

The outputs were also shorted. Aot412's should i check the drive signals before replacing the outputs? Will it show drive or is there another way?

 

[PapaZBill]

Did you check the AOT412's out of circuit? They may appear to be shorted in circuit, due to a latch condition of IC4-IRS20957

Have you been able to reestablish the power supply rails? If so, assuming the gate resistors 4.7 ohm are in tolerance, replace the AOT412's and check for drive. etc.

 

[rhempz01]

Yes, i generally test transistors in a tester once pulled from circuit.
Still waiting for the aot412 to come in all i have are the aot410 from the 1200.1's

 

[rhempz01]

Aot412 came in so i replaced them. Still no audio. Does not draw alot of current but the new outputs do heat up a little, so i shut it back off.

 

[rhempz01]

It just has the red protection led dimly lit, and its fluctuating current slightly.
Both power supply had drive signals before i installed the output transistors, as soon as they were installed, back into protection. So is it the irs20957s?

 

[PapaZBill]

Take a look at IC7-LM311 with a scope Pins 2,3 and 7 both with and without signal. Measure the DC voltages around the IC and post screenshots and voltages.

 

[rhempz01]

1.) .002
2.) .002
3.) .004
4.) -15.43
5.) 14.75
6.) 14.75
7.) 2.424
8.) 14.87

 

[rhempz01]

pin 2 without signal.

 

[rhempz01]

pin 3 without input

 

[rhempz01]

pin 7 without input

 

[rhempz01]

pin 2) 40hrz 5v input

 

[rhempz01]

pin 3) 40hrz 5v

 

[rhempz01]

pin 7) 40hrz 5v input

 

[PapaZBill]

Look for U7-2068 at the input. With signal, check to see if you have output at U7-Pin 7.

If you have signal and you can manipulate it with the gain control move forward to IC6-2068 Pins 3 & 4 near PWM.

If you don't have signal move backward to U6-2068 Pins 7 & 5,and U5,U4 etc to the RCA's if necessary.

How hot are the outputs? This may be normal. If they are not shorting you should be okay. I think there is an interruption in the signal path.

 

[PapaZBill]

Check R130,131-1 ohm smd. They appear to be cracked.

 

[rhempz01]

they are, thanks. and way out of tolerance. what size are they?