Recent content by greniu

Hi Dave, Thanks for quick answer.On the video you can see text shaking a little (pulsing). It is normal? Maybe I'm looking for something that is normal in all PET from these years? But please zoom the video on youtube and you can notice this pulsing.

hello. Does anyone have any suggestions?Thanks

Hi Dave, Thank you for all advices. I really appreciate. I apologize for not answering. I was on holidays, so I had no time to make further tests. Please see video with my situation (I uploaded it to YouTube): Video of the PET text wobbling During this video the PET monitor was connected...

Hi Dave, AD. 1. You are right I connected ground probe clip to PCB ground. Do you have any other ideas what to check? Is there any other suspicious component I need to check for this behavior? Thanks

Some new measurements: 1.AC voltage across CR19,CR21 (before rectification): 2.DC voltage across CR19,CR21 (after rectification) and that goes to C1 (+): 3. DC voltage across C3 (after regulation from VR1):

I also did 3 tests to check magnetic interference dependency, because something was not clear to me. The results really confused me and surprised me. Test 1 - I put monitor in its oryginal position (on PET case) ant turn power on. I was able to see whole text on the monitor wobbling a little...

I have measured DC voltage across C17. This is how it looks like. Is it normal?

hi Dave, I have swapped R20 potentiometer and no change. I will look for other advices.thanks

Hi Dave, Thanks and very appreciate any advices. So do you think that changing this R20 will not help with text wobbling? When I was touching this (with finger or plastic screwdriver )I noticed screen pulsing, and when changing potentiometer value the screen changed vertical size. But during...

hello. I think I have found a root cause. This is R20 (1 M ohm) on schematic. Does anyone know the replacement or the part name to find? thanks When I touch it I see the text shaking on the screen. I suspect it is broken or not conducting electrity corectly. I have tried to clean it and deoxit...

hi Dave - videoboard in my case is monitor PCB. I will try to re-solder those joints and do a measurements. Any other ideas what I should look for? I am pasting HSYNC signal from scope. When I zoom it I can see a strange peak line

hello, I recapped videoboard today. No difference. I have noticed that when I move VDU further away the PET I see only first line shaking but it was when I took the board out of the metal VDU case. I also applied some Deoxit onto Q9 potentiometer , because when I tried to touch it, the whole...

Hi. This is video from PET CRT (attached). The text shakes.I haven’t recaped it yet.

This is very strange. I used "Auto Calibrate Video Sampling" in RgbToHDMI device menu and I can see static picture now! So sampling probably misled me and I thought that there is something wrong in the mainboard. ahhh. So does it mean the mainboard TTL video signals are working correctly? I...

hello, Here is recording from the captured picture.