Kicker ZX300.1 going into Protect mode, I need help
First, I am new to repairs. I have Perry's repair tutorial that I am working my way through, but because of all the info that it has, it is somewhat overwhelming.
On to the problem/question: :(
I have a Kicker ZX300.1 monoblock that flashes Green to Red.
The circuit board has a date of 14-04-2006 and is a Rev 1.2
I have remove the output transistors from the board and checked them and they appear fine to me. They read as the tutorial says that they should. There are (3) C5242A and (3) C1962A. They are connected to a large ceramic resistor each, which has 5W0.2ohmJ printed on the sides. I measeured them with the transistors out of the board and they appear to be within tolerance. :confused:
Here are the voltages on the TL494 IC
1) fluctuates from 1.07 - 1.22
2) 3.3 :)
3) 0 and then up to 5 when the red protect light flashes :eek:
6) 3.42 :)
7) 0 :)
8) & 11) 4.5 then fades to 0 when the red protect light flashes :eek:
9) & 10) 1.67 then fades to 0 when the red protect light flashes :eek:
12) 12 :)
13) - 15) 5 :)
16) 3 then climbs to 9 when the red protect light flashes
Nothing appears to be burnt on the board
I do not have a scope and know that I need to invest in a better meter. With that being said,
Any help and direction is greatly appreciated.
Post a photo of the board.
As much as I know that you do not like them, these were taken with a cell phone. It is the only thing I have at my disposal until much later.
There is also a small circuit board that is not pictured that sits elevated on the end with the RCA's. I think it is the crossover section because it has the swithech for that on it (and the bass know input).
Is there a small transistor directly connected to pin 16 of the TL494?
In the third picture from the top, pin 16 is in the lower right corner. Just below it is a capacitor. To the right of the capacitor is a Zener Diode and to the left are two light blue resistors. These are all connected to pin 16 by a trace on the bottom of the board.
Here are the component markings and board designations
Zener - 48 - D6
Cap - 104 100V - C1
Res - brown, black, red, gold, brown - which I interpret 1000 5% 1% - R50
Res - brown, red, brown, gold, brown 120 5% 1% - R3
I may be interpreting the values wrong.
Desolder 1 leg of the diode (not likely a zener and likely marked 1N4148). Does that allow the amp to power up?
I strongly recommend clamping all semiconductors tightly to the heatsink and inserting a 10-15 amp fuse or a current limiter inline.
With 1 leg of the diode desoldered & removed, the amp powers up and does not flash the red protect light, it just stays Green. :)
Does that diode connect to a transistor in the audio section of the amp? There may be a resistor in series between the diode and transistor.
The trace connects to two capacitors and a resistor and it ends at an emitter (left leg) of a 2N 4401 (Q6). This transistor is located in the middle of 3 rows below the IC, last on the right (third picture from the top).
The capacitors and resistor jumps to another trace that connects to another emitter of a 2N 4401 (Q9). Two more capacitors and a jumper are also connected to this trace. This transistor (and the two capacitors) are in the bottom of the three rows and is located just above the top right yellow capacitor.
Reinstall the diode and remove Q6 and Q9, one at a time. Which one, when removed, allows the amp to power up?
Can you post better photos for this area of the board so that the circuit board designations are legible?
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