Monitor switching to 31khz gives image not centered

[Supersonick]

Hello,
I am reading this forum since long ago.. only now I am wryting as I have some problem with arcade monitor Makvision M3129DF-TS . I am using Grovymame, and the problem I have is with 31khz games like Wargods, NFL Blitz etc.. when monitor switch to 31khz the image is not centered, half of it is out of the monitor (to the left) and the rest of the monitor is showing black/grey area..
is it something I can fix with .ini parameters editing in MAME or Switchres?

thansk for the help.!!

[Calamity]

Hi Supersonick,

Have you tested the 31 kHz range with another source, like a normal VGA resolution of 640x480@60Hz (e.g. the Windows XP boot logo)?

You need to determine if the hardware ranges in your monitor are to be adjusted because they're relatively off centered, or instead it is the software ranges in GM what need to be adjusted.

But IMO if you're seeing half of the monitor out then it's something to do with hardware.

[Supersonick]

Hello Calamity, yes I tried and definitely even XP boot logo is way off the left.
So it is hardware problem. Do I have to play with potentiometers? So that I will need to do everytime I want to play a 31khz game?
Thank you.

[Calamity]

Hi Supersonick,

I don't know about your Makvision, but for instance the Hantarex Polostar has specific potentiometers on the E-W board to modify the relative shift among frequency ranges (15/31 kHz). You'll need to check the service manual of your monitor to see if there's something similar.