CRT TV - Brightness is too high

[Flybacks]

Hello, I'm trying to fix a Grundig CUC 2401 with picture brightness too high.
The problem seems to be in the brightness voltage supplied by pin 16 of TDA8442 that should be in the 1-3V range instead it is about 3.2V.
If I manually lower the brightness the voltage goes in the right range of about 2V and doesn't increase but I don't understand why at start up it is set wrong ?
I've already changed TDA8442, the video output IC TDA3505 and the microcontroller IC811 but it didn't fix.
The collector of RGB transistors on crt board are about 170V for red and blue but 150V for the green, shouldn't be all equal ?
Could someone please help me to troubleshoot it ?

Schematic: https://elektrotanya.com/grundig_cuc2401.pdf/download.html
The TDA8442 is at page 4

Many thanks!

 

[bertus]

Hello,

It could well be that the G2 voltage is not correct:
https://shmups.system11.org/viewtopic.php?f=6&t=67477

Also the following page will likely help troubleshooting:
http://www.repairfaq.org/sam/tvfaq.htm

Bertus

 

[Flybacks]

Hello,

It could well be that the G2 voltage is not correct:
https://shmups.system11.org/viewtopic.php?f=6&t=67477

Also the following page will likely help troubleshooting:
http://www.repairfaq.org/sam/tvfaq.htm

Bertus

Hello, G2 voltage is correct. If I lower brightness manually the picture is fine and brightness voltage on pin 16 of TDA8442 is set correctly, I just don't understand why at start the voltage of pin 16 is too high ?

Could someone look at the schematic and help me to troubleshoot it ?

Thanks