kicker kx 650.4

I have a KX 650.4 that appears to be electrically dead. The amp has seen limited use and has never been abused. It worked one day,and the next day it didn't. I've checked the two 40 amp fuses in the amp and neither was blown. No led's are lit up. I pulled the amp to bench test it,as best that i was capable of. I did a close inspection of the circuit boards and didn't see any obvious signs of burns,scorching,etc. I didn't see any obvious broken solder joints on the board,but i didn't remove the board from the heat sinks for a closer look either. I powered up the amp and made sure that there was 12 volts thru the fuses and on the remote lug and figured this was my stopping point. I have an extensive background in electrical process controls,but a  somewhat limited knowledge of intergrated circuitry,the components,their electrical values,properties and basic function. If someone has a better understanding and can point me to the next step in diagnosing the failed part it would be greatly appreciated. Or possibly recommend a  reputable repair facility in the Dallas,Tx area. Thanks.Terry

Do not take the amp apart yet.  In the following picture the 2 clamps to the left of the picture do need to be removed.  Top left and bottom left clamp.  With the amp disconnected, meter set to the diode test function.  Below is a picture of the symbol that should be on your meter somewhere. 

Touch and hold one lead to the positive terminal of the amp, now touch the metal tab of one of the transistors that were uncovered by removing the clamps.   Do one transistor on top of pic and one on the bottom of the pic.  It should beep at you and read very near 0.000.  Now touch and hold one lead to the negative terminal of the amp, other lead to the rightmost leg of the same transistors you checked the tab of earlier.  Looking at the transistors when you can read the letters and numbers on the part is how you determine the rightmost leg.  Let me know what you find out. 

You did use a volt meter to verify that you had power on both the remote and power terminals.  When testing these voltages, hold the black meter lead to the negative terminal of the amp. 

First i'll send an apology for not getting back sooner,workin that a... off. I did as you said and the meter went to zero when checking between the positive terminal and the metal tabs. The meter also went to zero when checking between the negative terminal and the right most legs of the transistors. I'll wait for your response to see where to go next. Have a great holiday and thanks for the help.

There is a chip in the middle of the board, near the transformer, what is the number on that chip?  TL494, TL594, SG3525, SG3524?   I need to know the DC voltage on each pin of the chip.  Be very careful to not touch 2 pins at once, especially 7 and 8, and 10 and 11.  With the chip sitting so you can read the numbers, pin 1 is bottom left, pin 8 is bottom right.  9 is top right, 16 is top left.  If it is a 494 or 594, Pin 8, 11, and 12 should have 12 volts.  

You will have to connected to remote, power, and ground to perform the above.  Black meter lead to the ground terminal of the amp.  Red lead to each pin. 

Ok, The chip is a TL494CN and the voltage measurements are 1=.3, 2=.9, 3=.0, 4=.0, 5=.0, 6=.0, 7=.0, 8=1.1, 9=.5, 10=.5, 11=1.1, 12=2.2, 13=1.4, 14=1.4, 15=1.4, 16=4.5.  

Remove all the fuses from the amp and insert a single 10 amp fuse in one of the slots. using your meter lead, short pin 12 to pin 11 briefly, this should make the amp come on.  We need to figure out why pins 8 and 11 are not getting power.  If this makes the amp turn on, we have verified that lack of power on 8 and 11 is your problem.  Remove power from the amp.  Very important.  With your meter set to ohms, or 20 ohm scale if it is not an autoranging meter, how much resistance is there between pins 8 and 11?  If there is near 0 ohms between them, look for a 100 ohm resistor very near one of the pins.  Brown Black Brown will be the first few bands of the resistor.  Check it to see if it is reading well over 100 ohms.  Also look for a transistor very near labeled on the board as Q1.  If the resistor is ok and you find the transistor, let me know, I will tell you how to check it.   DO NOT remove any part from the board, and do not remove any more clamps from the heat sink yet.  If you read the last post before I deleted it, I thought pins 9 and 10 were 5 volts.  It was not till I read it this morning that I noticed the decimal point.  5V good  (.)5V not so much.

Also look for  a diode very near those components.  Place your meter on the diode test function again and place a lead on each end of the diode, notice the reading, now reverse the leads to the other end and notice the reading again.