Hi folks,
I was performing the CAL08 procedure as suggested in other trend to fix a four rows of dots that are showing on the screen.
First, I could not adjust grid bias trimpot (R1878) because the spot was MUCH MORE brighter than the line of dots for the entire pot range.
The the display flickered and the dot became a lot less brighter but still brigter that the dots, but I decide to move on.
When I started the geometry adjustment moving R4350, the scope rebooted and the vertical position controls for all the channels are not working
The scope is able to display the calibration signal, but it is high "up" for CH1 and CH2.
Just in case I checked the voltages at J119 and they are all fine.
I went to the troubleshooting chart but it is very "vague" to me.
It says " if the problem happens on the four channels the problem can be:
1- channel switch
2- delay line
3- Vert Output Amplifier
4- Hybrid Power Suplies
I do not have enough knowledge to proceed.
Any suggestions?
Thanks to all,
Roger