Picture rolling on some GM games

[someoneelse]

Hi!

I finally got Emudriver to work and all emulations are running really smooth. 

Still there a some GM games that slowly roll horizontally, it seem's the CRT (Hantarex MTC9110) can't synch correctly to these games for some reason. Playing with v-hold will make it roll faster or slower, but it never comes even close to saying stable.

I've tried to investigate what's going wrong by searching for similarities in the logfiles of these games, but can't find any connection. It doesn't seem to be linked to orientation, interlaced or not, certain resolutions or frequencies.

Maybe some of the more experienced users can have a look at the attached logfiles of two games that produce the rolling picture and can push me in the right direction? Are there any settings in GM I can play around with on game level to try to make the picture stick?

Thanks!

EDIT: I've attached some more logs of rolling (fail) and working (ok) games.

[Calamity]

Both logs have in common that the refresh is somewhat low (57 and 55 Hz). But you should be able to find an v-hold setting that covers at least 10 Hz, from 50 to 61 Hz more or less. If you can't find that setting, either your monitor controls board is faulty or the way your sending the sync signals to your monitor is the culprit. How are you connecting your monitor?

[someoneelse]

I'm using a J-Pac, jumper set to let only 15K synch pass. Card is a HD4890.

I've got a NIB MTC9110 from which i borrowed the control board to test it with the 9110 in the cab, but that makes no difference.

I did notice that the failing games are close to the 15625Hz lowest limit and the good ones have at least 157xxxHz, maybe that has something to do with it?

[Calamity]

If you can, post a video. You say horizontal rolling and v-hold in the same sentence which doesn't make sense. I have two MTC 9110, it's a monitor I know quite well.

[Calamity]

I did notice that the failing games are close to the 15625Hz lowest limit and the good ones have at least 157xxxHz, maybe that has something to do with it?

Sure. Adjust the H-freq pot instead of V-hold.

[someoneelse]

I'm meant to write h-hold, sorry for the confusion. So I'm using the correct control, but I tested both anyway. 

I've made a short video of a rolling game while very slowly adjusting h-hold all the way from side to side. It's pretty hard to hold the cam while trying to reach the control board...

[Calamity]

Try increasing the minimum horizontal frequency in the crt_range in mame.ini, to 15.750.

[someoneelse]

Tested it, but it doesn't seem to have any effect at all, the rolling is exactly the same as with lower frequencies. I've attached the log from the test.

[someoneelse]

Ok, now this is strange: I restarted the CRT in a now very warmed up state and the picture is stable now. Reduced the frequency in mame.ini to the original value...still it sticks.

I think this is actually a problem on the chassis! I'm suspecting IC2 might have a problem, so I know where to go from here. 

Thanks a lot for looking into this!