Response from Jonathan: Cedric,

Looks like it’s either a problem with the horizontal hold adjustment or the b+ voltage. We recommend adjusting these pots to see if it makes a difference in your picture. Check out our post on Adjusting An Arcade Monitor for more information.

Bad news is that this is probably not a problem that can be fixed the normal methods (i.e. cap kit, flyback, HOT replacement) if the adjustments don’t help your issue. It would probably be best to contact the seller to see if he can help you out or ship the monitor chassis off for repair. Check out our resources page under the Monitor Repair Services & Information for a list of people we recommend for monitor repair. Of course, if you’re pretty familiar with electronics and using an oscilloscope you might be able to do this yourself. Just depends on your knowledge / comfort level.

Hope that helps. Thank you for your question and good luck with your repair.