CRT Monitor Jumps

Joined
Jan 17, 2018
Posts
8
Hello!

Recently, my cab's CRT display jumps. Every jump has a chance of altering the image to be displayed up to several noticable horizontal lines lower than normal or back to default if it was already displaying lower at the time of the shaky jump.

I looked into the forum's backlog, but the closest solution revolved around the issue being sudden visual flashes causing a spike in voltage to the monitor.

However, after extensive testing, the screen appears to be the case even when idling when waiting for a shot in Neo Turf Masters, idling in game menus, waiting in fighting game character select screen/matches, and even when sitting in the UniBIOS menu.

Apologies if this has been asked/resolved before, but I would appreciate any resolution or advice.

Thanks in advance!
 

Kid Panda

The Chinese Kid
Joined
Jun 13, 2010
Posts
12,514
What kind of monitor? Usually the remote board is the culprit or a wonky ribbon cable going to the remote board. Pics would help as well. It's hard to diagnose with the vagueness.
 
Joined
Jan 17, 2018
Posts
8
Sorry for the vagueness.

The monitor itself has no labeling, but the chassis is for a Wells Gardner 19K7610. It could be the cable between the MVS board and the monitor. I only have one such cable, so I can't troubleshoot between several, at the moment.

The following link shows several images of the monitor. The last two, while very similar, do somewhat show the jump effect if you compare them side by side.

https://imgur.com/a/k68ND
 

MKL

Basara's Blade Keeper
20 Year Member
Joined
Mar 8, 2002
Posts
3,686
It's the Zenith version of the K7000, also known as the K7000A. It's almost identical to the Wells Gardner version except for a few changes in the horizontal deflection, the flyback in particular. The screen pictures we're supposed to compare to each other aren't very helpful but the other pictures show the flyback has been messed with. Normally there should be a second wire coming from the anode cap and going to a big epoxy block that contains a bleeder resistor connected to ground:

K7000A.jpg

It looks like someone cut it off and put some insulation tape which is a terrible and dangerous thing to do. The lack of this resistor may well be the culprit. Were it not for this I'd suggest to tweak the vertical hold trimmer, assuming it's the kind of jump I have in mind. Bad solder joints and trimmers could be another cause.
 

Hine62

Krauser's Shoe Shiner
Joined
Jul 15, 2005
Posts
230
It looks like the chassis needs to be cleaned. You can search youtube for some help. I cleaned mine with air and it seemed to help some problems. I also did a cap kit and changed some diodes that were bad. You may have a cap failing or a loose wire.

You might also try pushing, gently of course, the board back on the tube. These guys have some good videos Arcade Repair Tips

I agree that taped anode wire is a not a good thing. Don't mess with it unless you know what you're doing. Do some research on how to discharge the tube. Then replace the flyback.

I got some parts for my qnic chassis here: arcadepartsandrepair
Also you might check the klov forum

Good luck, I did mine. It wasn't that hard.
 
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