I checked out all other threads, (that's how I've gotten as far as I have) but, I sure could stand a schematic of this beast. Found 3 output Fets almost shorted,(aka hand grenades & Horseshoes) which I pulled and got relay to click. Didn't have any thing like this so, I pulled one of the good outputs from the good side,(even double checked it with my fluke) and placed were the leaky Fets were. It got rostie no time flat while good side stayed cool to touch. Drivers out of circuit seemed fine so am I looking at a digital driver bad or what?
The schematics are not available for proprietary reasons. I work in the electronic repair department at Kicker and I've worked on many of these amps.The protection LED toggling is a sign that the output FETs are shorted or there is a problem in the Class D circuit or driver stages. After you pulled out the shorted FET's did you ohm out the location where the FET's were? You should see 47 Kohm from Gate to Source leads(outside to outside pin locator), and all other checks gate to drain and source to drain(middle to either outside pin locator) should be in the megohms. What model year is this? Should be a date stamped on board and the 06 will have red rubber seals on the cover and there are four chips under the daughter board which is the two driver circuits one each for banks of three output FETs. The 08 or newer have these chips closer to the output FET's.
What output FET's are in this board, the outputs where replaced with IXTQ36N30's. I believe the original FET's were IRFP264N, but don't hold my feet to the fire! You can pull out the Class D daughter board and preamp/xover board. If the amp is still toggling in and out of protection you can left up D7,this should allow you to check the main and small power supply among other things.
Sorry for the time lag..Answer to your 1st question, No, but Good idea. This will be my 2nd thing I'll do, (the first will be to figure out Q 24-27's driver Polarity NPN-PNP?"long story". 2nd question It's a June/10th/08 model.3rd,IXTQ36N30's and the protection stayed off when the shorted finials were pulled. Thanks for your input. Work'n on something this sophisticated without any documentation,( except the simi's themselves) is like that TV show where folks are in a pitch-black room trying to figure out what the heck there grabbing a hold of! This monster is NOT a class A/B,(Or A,B,or G).D's I thought were more like a DAC or a Horizontal output on a CRT,a square waveform amplified to a transformer turned into a sine wave. I don't think I've heard a full bandwidth class D amp, (don't see how they'd sound all that good)
this is a class D sub channel mono block, not fullrange stereo. Basically the LM361is a comparator, whichs samples audio referenced to a triangle wave. The results modulate the pulse (PWM). this gets passed through the drivers, ouput mosfets and the output inductor acts as a d to a convertor. hences audio to spkrs. Q24,27 Is 2SD667 npn & Q25, 26 is 2SB647 pnp.
Thank You for the Brain Pick! Yes a comparator,( still the output is just a facsimile of the input signal, right?). I still remember some electronic Theory,(ELI the ICE man,the resistor color code saying), but have found out over the years that Murphy's law and not Ohms seems to prevail. The output drivers threw me,JE 171 &181? When I was look'n for output fets, a tech at Newark said FCB36N60NTM (MOSFET, N CH, 600V, 0.081OHM, 36A, TO-263-3) would sub for
IXTQ36N30's which I didn't find right-off. Thanks again, I will reinstall the bipolars and check DC voltages,(again). Hope to find out what fried the originals.
IXTQ36N30's which I didn't find right-off. Thanks again, I will reinstall the bipolars and check DC voltages,(again). Hope to find out what fried the originals.
No, The PS seems OK!! I had it running,(with Q 106,8 and10 pulled and the rest still untouched). It draws close to a Amp @ idle & The board was naked on my bench. Everything seemed cool, (That's why I was reluctant to jerk the output drivers) but, ½ of the output circuit was missing and without a schematic to go by I didn't know what to do. I got like a hundred volts DC +&- that's why I removed a good out and stuck it on the other side. When it got hot I knew something (open/short or leaky) was going on.
The Relay would Click,(close?) when fired up with just the shorted outputs removed. How long do you wait for the electrolytes to discharge? The “inductor”.(looks like a output transformer) Copper windings looks shinny with No hot spots. That's what made me Leary to begin with. It look like one side of the finales got drove into saturation & the other was in cutoff by the input signal. This thing has one of highest DC voltages I've seen on a mobile amp,(bet it would knock ya on your butt if you weren't careful). Do you think I'll need to scope the gates or can you tell with a meter? (I just got rid of Betsy, My old B&K 10mhg single trace CRT back in the fall). Power supply ripple and a home made curve tracer was about it was good for when the H position trimmer went south.
Remove power and let it sit an hour, probably overkill, but better safe than sorry.Unless the inductor is considerably discolored or has a darkened spot it should be okay. Checking the resistance between leads of output mosfets,outside to outside(G to S) whether the mosfets are in board or not should be 47Kohm. All other resistances checks middle to either outside leads should be in the high Kohm to Megohm.
Sorry about The really Long delay, (My wife has Lupus & average days have become Not so average). My friend that owns the Beast on my bench needs another, (Yea, he's got a second one), And I told him I wouldn't have got as far as I did without your input & that 1 fellow worked on this things of a living just a state over. He wanted me to ask if he could purchase 1 like his after you have serviced it? He's getting ready for warm weather & putting it his boat, ( I bet it stuns the fish when it's Cranked up) Thanks
Sorry about your wife, I hope she is feeling better.
Can you send some pics. There are some differences between the 2006 and 2008, and I can easily determine which of the boards you have.
I'm not sure what your friend is asking, we don't make this amp anymore but you may be able to find one online for sale
Can you send some pics. There are some differences between the 2006 and 2008, and I can easily determine which of the boards you have.
I'm not sure what your friend is asking, we don't make this amp anymore but you may be able to find one online for sale
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