GZTA 1.1200

[Perry Babin]

Negative rail as reference, DC voltage on pins 1, 12 and 14 of the driver IC?

 

[mika111]

1. 0,03
2. 0,00
3. 0,00

 

[Perry Babin]

Pin 7 of U107?

 

[mika111]

10,83

 

[Perry Babin]

What is U109?

 

[mika111]

I cannot find U109, but those other 8pins are 4558

 

[Perry Babin]

U108? I misread. U108 makes sense. The IC between the driver IC and U107.

 

[mika111]

Oh yes..

 

[mika111]

Another picture

 

[mika111]

74HC02D
L3A0E142
UXD1403D

Maybe 😀

 

[Perry Babin]

74HC02?

Voltage on all terminals, negaitve rail as the reference.


Pin 1:
Pin 2:
Pin 3:
Pin 4:
Pin 5:
Pin 6:
Pin 7:
Pin 8:
Pin 9:
Pin 10:
Pin 11:
Pin 12:
Pin 13:
Pin 14:

 

[mika111]

Pin 1: 0,00
Pin 2: 1,01
Pin 3: 1,01
Pin 4: 0,00
Pin 5: 0,00
Pin 6: 0,00
Pin 7: 0,00
Pin 8: 0,00
Pin 9: 0,00
Pin 10: 0,00
Pin 11: 0,17
Pin 12: 0,00
Pin 13: 0,00
Pin 14: 0,17

 

[Perry Babin]

It doesn't appear that the power supply is running. What's the DC measured across pins 4 (black) and 8 of U107?

 

[mika111]

It may be, because the Q12 is out of board? Just a minute...

 

[mika111]

14,22VDC

 

[Perry Babin]

OK, now the voltage on all terminals of U108.

 

[mika111]

They're the same

 

[Perry Babin]

Pin 14 of the 74hc02 should have supply voltage.

Measure the DC voltage on U107 pins 4 and 8 again, using the secondary ground as the reference.

 

[mika111]

Pin 4: -14,18
Pin 8: 14,23

 

[Perry Babin]

How did you get only 14v across 4 and 8 when you read ±14v on those terminals?

Do you have 12v (referenced to the negative rail) on pin 11 of the driver IC?