Question from Daniel: Thanks again for all your helpful videos! Been learning a lot with you guys on YouTube! Got a quick question for you: What is this screen symptom called? Vertical fold over? A vertical sync issue?

– Here’s what the picture looks like when connected to PC: https://youtu.be/pYXd0VgdApQ
– Same issue connected to JAMMA: https://youtu.be/1uGRs-uuLzg
– Same issue with no video input connected and flyback screen brightness turned up: https://youtu.be/Mzaen2wGTCc

This happened immediately after changing the HOT, voltage regulator, and B+ filter cap. Afterwards I put all of those original pieces back in but it was still doing that. Thanks, Daniel

Here is a brief summary of this cabinets history from the time I got it until now, if interested:

1. When I originally got the cabinet the flyback was probably blown. CRT was basically dead. Very dim screen. Replaced flyback, did cap kit, swapped tube with a TV tube. Used the TV yoke because the readings were acceptable and very near the original. Arcade game looked brand new again. Great colors. Needed a little degaussing but picture was perfect after degauss.

2. After that, once in a while screen would do a quick 1 or 2 second flash at random points while playing it. This usually seemed to happen more often during points of a game that had a lot of action going on. Sometimes immediately following the flash the screen seemed to resize itself a little smaller and maybe even a little darker than it was before, and sometimes it would start to wave like a water effect at this point…then after maybe 30 seconds it would flash and go back to a normal looking screen again. Blowing a floor fan into the cabinet seemed to alleviate this considerably, but I’m not sure if that was true or just coincidence.

3. I decided to change out the HOT, voltage regulator, and B+ filter cap to see if it would stop the problem. Instead I ended up with this after putting those in.

4. None of the pots will fix this. Not even the 50/60 pot

5. I tried putting the original old HOT, voltage regulator, and B+ filter cap back in but that didn’t fix it. So I put the new HOT & voltage regulator BACK IN the chassis again and that’s how its set up now. The old B+ filter cap is still in the chassis, I did not put the new one back in again.

6. B+ reading was 161.9 on one terminal of the 180ohm resistor and 120.2 on the other terminal of that same resistor. That’s with the new voltage regulator installed (and yes, its a 30130). With the OLD original 30130 regulator, the B+ measured 161.3 on one side and 107.3 on the other side.

7. Q9 tested OK both forwards and backwards.

8. Tested IC3 – I got 22.5 volts. (IC3, pin 6, monitor turned on, black lead to ground, red lead to pin 6.

9. Changed out the vertical IC 3 with a new one (same model # as original).

10. Checked continuity on all the joints of the board. Reflowed some old joints.

11. I did another cap kit with better quality capacitors.

12. Checked the ohm’s on the yokes green & yellow wires. Readings were OK.

No luck so far