This there a flip screen option for the mvs?

I recently bought a cabinet for converting to a mvs machine, however, the monitor displays upside. is there any switch to flip the screen?

no.

If the monitor is _really_ in the correct orientation, and displaying incorrectly, you're going to have to start messing around with the sync wires on the chassis. There are four wires, two pairs, one each positive and negative for both the vsync and hsync. Probbaly, the polarity is reversed on the vsync but mess around with all of them until you get the picture looking right.

Be careful not to electrocute yourself. Do not wear a grounding strap on your wrist.

I would guess the monitor was rotated for SHUMP play, which means normal games would display on their side. Depending on your cab it can be really easy or really hard to orient it for standard jamma games.

Heres a good write up on yoke flipping, its what you will have to do to correctly orient your picture.

http://www.homearcade.org/BBBB/yoke.html

Whomever converted the cab originally must have had the "flip" switch on on the game they install and put the monitor in upside. Originally it was a zaxxon and then it was converted to a horizontal game. I'll just have to manually flip the monitor over and re-install it. No problem... thanks for the info tho.

You could split the deflection yoke plug snd reverse the scan.