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dartssport 20th May 2013 02:33 AM

ZX750.1 up in flames.
I have a ZX750.1 Kicker monoblock, when I hooked it up it was like the forth of July. :eek: I pulled it and replaced it with an other ZX750.1 and works like a champ. I pulled the board and all of the IRF3205's are fried. And this amp is a little different then the last amp I worked on, the (I believe) gate resistors are little black squares with 101 and some with 104 stamped on them. is this the resistance or is it some kinda code? What voltage should i see at the pins? also i dont see any driver transistors anywhere on the board. Ill post some pictures, Perry was a great help on the last one i worked on(still waiting for some parts for over a month)..
and help would be great.


dartssport 21st May 2013 12:38 AM

Ok from experience I know the PS is shot but Im not sure what caused it so I and gonna replace the PS, Driver Transistors, and the output transistors and well as the gate resistors. I was told that the 101 stamped on the resistors is 100 ohm?

Heres my parts list any crossable part numbers would be greatly appreciated.

IRF3205 x 8
IRF9640 x 6
IRF640 x 4
100 ohm resistors x 8
ASG23 drivers x 2

Now ive never heard of a ASG23 transistor and wonder if 100 ohm resistors is too much, not enough deadtime?

Ok all you pros out there am I missing anything??

How much should the rail voltage be?

any info at all please

dartssport 5th June 2013 11:24 AM

47 ohm or 100 ohm resistor
Has anyone actually used a 47 ohm resistor in a zx750 instead of a 100 ohm resistor and it worked?

Is a KTA1504 a good replacement for a ASG23 transistor?


dartssport 23rd June 2013 07:54 PM

This message if for the administrator, could you please move this post to the Car Audio forum please?

Salas 24th June 2013 04:45 PM

OK. :captain:

dartssport 3rd July 2013 03:21 AM

Ok I removed the 8 irf3205's and the 2 transitors i believe are the drivers, cleaned the board up, hooked up some power and am getting 12v on the center leg and 4.4 volts on the end pin (other end pin is ground) ok now I need a cross reference for the driver transistors. Should i switch the 101 ohm resistors with 47's?
Perry was a great help on my last amp so im hoping he can help me out or anyone for that matter.

seankane 4th July 2013 05:43 PM

Use the IRF3205's and switch the gate resistors to 47 ohm. Replace the driver transistors for the power supply as well.

Check all the outputs for any shorted.

Do you have a scope?

From what you said the voltage that you are getting at the solder pads, it looks like your getting gate voltage to the power supply FETS.

Not knowing the history of the amp, either someone reversed polarity on the power supply or you have some shorted outputs.

dartssport 4th July 2013 05:50 PM

I do not have a scope as of yet. I will check the outputs. Do you have a recomendation for a good inexpensive scope?
Thanks for replying I started to think the forum was dead.

seankane 4th July 2013 07:17 PM

I would look for a good used Tek465 or Tek465B. Thats what I use and they work awesome. Just make sure it comes with probes and it has been recently recalibrated.

seankane 4th July 2013 09:59 PM

I have been informed from a reliable source that you can use the 100 ohm gates with the IRF3205's in this amp. You can do this because Kicker programmed dead time into the drive circuit to allow for it.

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