Kicker 083ZX1000.1 output trouble

[rhempz01]

OK so I am starting a zx1000. 1 amplifer seems to be running in perfect order. 13.3vdc it draws after the relay engages 1amp of current. Regulated voltages are present on the class D card and the input card. I traced my 40hrz from input to class D card as well.
So I checked u202 pin has a nice triangle wave. No driv from. Pins 8&9 so I'm thinking its the ic that's bad?
So when I changed it the amplifier started flashing in and out of protection.

 

[PapaZBill]

If you lift D7-1N4148 does the amp come out of protection?

Check the voltage across C11 and C12. Both should be 18Vdc. This is an aux power supply independent and isolated from the main supply. This supply consists of U1-TL594, T1,Q12 & 13-MTP3055(Mosfets may be different in your amp) and is the operating voltage for the Output Driver stage Q100,102-2SD669, U100,U101-MC33151(May be different in your amp),OPT100,101-2601.

You will have to remove the Class D board so you can check the voltages around the Driver stage and use the negative side of C11 and C12 for references. C11 supplies the Q100 driver (+DRV) and C12 supplies the Q102 driver (-DRV).

 

[rhempz01]

I lifted D7 and removed the class D card to check the voltages.
Voltage across
C12 17.01vdc
C11 16.95vdc
With the class D card installed and testing for voltages atop the card
+drv 4.815vdc
-drv 3.335vdc
Also, if I attempt to look at a sine wave on the speaker terminals and ground my scope to neg the relay starts to engadge/disengage over and over.

 

[rhempz01]

When I test the rail voltages at the output transistors and ground at signal ground.
Q106 106.32vdc (leg 2 center.)
Q108 106.31vdc (leg 2)
Q107 -105.01vdc ( leg 1)
Q105 - 105.02vdc (leg 1)
If I ground on the class D card and test the voltages
+-11.6vdc present
+4.65vdc present.
Drv+) 4.89vdc
Drv-) 3.77vdc

 

[PapaZBill]

List all DC Voltages around the following:

Use Neg pin of C11 for black probe
Q100
OPT100
U100
D100
D101

Use Neg pin of C12 for black probe
Q102
OPT101
U101
D106
D107

 

[PapaZBill]

When I test the rail voltages at the output transistors and ground at signal ground.
Q106 106.32vdc (leg 2 center.)
Q108 106.31vdc (leg 2)
Q107 -105.01vdc ( leg 1)
Q105 - 105.02vdc (leg 1)
If I ground on the class D card and test the voltages
+-11.6vdc present
+4.65vdc present.
Drv+) 4.89vdc
Drv-) 3.77vdc

The Drv voltages appear to be right

 

[rhempz01]

Voltages
Q100
1.) 10.71
2.) 16.74
3.) 10.86

OPT100
1.). 001
2.) 5.144
3.) 4.129
4.) 0.00
5.) 0.00
6.) 9.30
7.) 4.864
8.) 4.864
U100
1.) . 001
2.) 9.31
3.) 0.00
4.) 9.31
5.) .105
6.) 10.29
7.) . 104
8.). 001
D100
1.) .003
2.) 10.86
D101
1.) .001
2.) 4.865

 

[rhempz01]

Voltages p2
Q102
1.) 8.25
2.) 17.02
3.) 9.05
OPT101
1.) .002
2.) 113.8
3.) 112.5
4.) . 006
5.) 0.00
6.) 7.51
7.) 4.672
8.) 4.668
U101
1.) . 001
2.) 7.53
3.) 0.00
4.) 7.51
5.) . 101
6.) 8.05
7.) . 101
8.) . 002
D106
1.) 0.00
2.) 8.83
D107
1.) 0.00
2.) 4.652

 

[PapaZBill]

Voltages p2
Q102
1.) 8.25
2.) 17.02
3.) 9.05
OPT101
1.) .002
2.) 113.8
3.) 112.5
4.) . 006
5.) 0.00
6.) 7.51
7.) 4.672
8.) 4.668
U101
1.) . 001
2.) 7.53
3.) 0.00
4.) 7.51
5.) . 101
6.) 8.05
7.) . 101
8.) . 002
D106
1.) 0.00
2.) 8.83
D107
1.) 0.00
2.) 4.652

The voltages at OPT101 Pins 1 & 2 are much too high. You should be using C12 neg lead as your reference/black probe.

 

[rhempz01]

Confirmed voltages using c12 neg for reference.
Pin 2 111.2vdc
Pin 3 110.1vdc

 

[PapaZBill]

when you lifted D7 did the amp come out of protection?

It appears to have drive ~5V at DRV pins.Is there a squarewave in the gate circuit?

I'm not getting a clear picture of what is happening. It's be a few minutes since I ha one on my bench. They can be beast to troubleshoot.

Also, check the DC voltage around Q9,18,19,20-2N4401 & U3-74HC74 and post.

 

[rhempz01]

Yes lifting D7 brought the amplifier out of protection. I have no audio at the speaker terminals.
That high voltage is strange at pins 2&3 of otp101 grounded at c12, they are not present on opt100 unless I swit h from C11 ground to c12 then the same 112.2v is present at pins 2&3 of opt100.
Where should I be grounded to check the Q9, 19,q20,q18 set and the 74hc74?
I do not have a square wave on pins 9&10 of the lm361 but the triangle is present on pin 4
I have 40hrz getting to the card no 40hrz at speaker terminal.

 

[rhempz01]

Yes lifting D7 brought the amplifier out of protection. With D7 in curcuit if I ground scope to speaker terminal, it will trip the relay, I have no audio at the speaker terminals.
That high voltage is strange at pins 2&3 of otp101 grounded at c12, they are not present on opt100 unless I swit h from C11 ground to c12 then the same 112.2v is present at pins 2&3 of opt100.
Where should I be grounded to check the Q9, 19,q20,q18 set and the 74hc74?
I do not have a square wave on pins 9&10 of the lm361 but the triangle is present on pin 4

 

[rhempz01]

Someone has jumped a cap across q18

 

[PapaZBill]

The cap was factory installed.

Use speaker ground for U3 and Q9,18,19,20.

 

[rhempz01]

DC voltages without class D card in curcuit.
U3
1.) 4.810
2.) . 001
3.) . 001
4.) 0.000
5.) 0.000
6.) 0.001
7.) 0.001
8.) 2.251
9.) 2.594
10.) 0.001
11.) 0.001
12.). 0.001
13.) 0.001
14.). 4.881

 

[rhempz01]

Q18
1.) -0.041
2.) 0.020
3.) 0.001
Q20
1.) .001
2.) .020
3.) .001
Q19
1.) . 001
2.) . 020
3.) . 001
Q9
1.). 001
2.). 020
3.). 001

 

[PapaZBill]

If all of the Q9(-OCP),Q19(+OCP),Q18 & Q20(DC Protection) transistors check good with a ohmmeter/diode check U3 may be bad. Also check Q101-MPSA92(+OCP) and Q111-MPSA42(-OCP)

 

[rhempz01]

All those transistors check out. I changed the 74hc74 with one I had here. I do not know if it is good or not.
So. I learned that the Amp goes I to protection when I apply an input signal and turn the gain up. it stays green with D7 in curcuit until I add a input signal and raise the gain till about just under 1/2 gain.

 

[rhempz01]

All those transistors check out. I changed the 74hc74 with one I had here. I do not know if it is good or not.

So. I learned that the Amp goes I to protection when I apply an input signal, and turn gain up to about 1/2. This with the class D card in curcuit.