Electronics question - can't find replacement mosfets
 

I have a Kicker KX600.4 (car stereo amplifier) running 4 channels for my speakers. When installing, I was a moron and had the stereo on, and accidentally touched the positive to an RCA. Two of my channels were making static low volume sound, so I hooked my two other speakers to the two channels that work, but of course, my speakers aren't all playing the music they should be.

I opened up the amp last night and tested all the mosfets (multimeter on resistance touching the two outer legs) and found two that read less then 10 ohms. All the other mosfets read in the megaohms.

http://img717.imageshack.us/img717/213/chopped.jpg

http://img268.imageshack.us/img268/233/chopped2.jpg

They read,
on the left: ON; U1620R; CQ239; KAK
On the right: ON; U1620; CQ243; AKA

I can't find replacements online. All I could find is the U1620 for $9. Link to part: http://questcomp.com/QuestDetailsAll...3071&stock=Yes

Anyone know where I can find them or if I can substitute for a more common part? Thanks.

RE: Electronics question - can't find replacement mosfets
 

garbage pick or look at salvation army or goodwill for a donor, your bound to find a amp (or stereo) there.

RE: Electronics question - can't find replacement mosfets
 

oh yeah ive blown them up before , just take it to one of those places where they fit custom car stereo's and tell them to fix it for you thats what i did , you have to pay them for the fix of course.

RE: Electronics question - can't find replacement mosfets
 

try here www.jaycar.com.au just checked they ship to usa. link fixed

RE: Electronics question - can't find replacement mosfets
 

splcrazy, I tried that site and didn't find anything but thanks. I'll end up taking it to a shop if I can't figure it out myself, just trying to save a couple $$$ first though:D Also thanks The Shark (nice username btw [sm=48_48.gif]) for the suggestion.

RE: Electronics question - can't find replacement mosfets
 

What's the issue? The link you provided has the part in stock, U1620. The other numbers and letters are irrelevant. I believe CQ239 is the heat-lot number, which is used to link the part to it's origin and production date.

RE: Electronics question - can't find replacement mosfets
 

There's a U1620R which he seems to be unable to find. That's the problem.

RE: Electronics question - can't find replacement mosfets
 

I asked on an electronics forum and found out that these two parts are actually rectifiers, thats why they read different. They are probably both fine. Also I don't appear to have a burnt up transformer and none of the caps are blown. The only discovery that I have made is that when everything is plugged in, the speaker outputs where the speaker sounds the worst measure 1.75V while all the others read 0. Confusing...

RE: Electronics question - can't find replacement mosfets
 

Check those white ceramic resistors, you may have burned one of them up. Are there any Schottky diodes? Check them too, you should get a high ohm reading in one direction, and continuity in the other. Have you tried powering it up and sticking your nose down there to sniff for burnt stuff?

RE: Electronics question - can't find replacement mosfets
 

almost sounds like something is not grounding right.

RE: Electronics question - can't find replacement mosfets
 

I tested the resistors and diodes. I'm not sure if the resistance on the resistors means a thing since they were tested still attached to the board but I'm guessing they are fine. Plus they all read the same resistance anyways.

There is one diode on the board, it reads the same both ways, resistance in the megaohms. Even when attached to the board I don't believe this should occur. With positive touching the silver ring end, there should be zero connection. I've been working like mad but I should get around to changing it out within the next couple of days and I'll post what happens. Thanks everybody for the help and suggestions.

**update

I pulled the diode out, it reads normal when off the board so I soldered it back in. Bummer on that, back to ground zero...