problems with my CRT for some games

[DARKGATE]

  Hi guys, i have a SCHNEIDER CRT CTM 644 colour monitor, but i have problerms to display a some of games

TURRICAN (i have found on CPCPOWER a version wich fix the problem, but i have also the original tape, how i made for this version)

THUNDERBLADE 
ENLIGHTIMENT DRUID 2
I don't know if there are others games with this problem, but i can't display correctly, please someone can help us wich this MONITOR problem?
Thank you.

[CraigsBar]

Hi Darkgate, what is the error as seen? Is it possible to attach a video of the problem.

Craig.

[arnoldemu]

I am going to guess it will be these:

Programming methods used in games - CPCWiki

Under the "Rupture" section.

The reason you have problems is
1) The method used generates frames which are less or greater than 50hz. The programmer didn't get it correct. The monitor isn't happy unless it's perfectly 50hz.
2) The rupture runs fine on some CRTCs but not all. This is an example of a CRTC incompatibility. The programmer didn't get it right and didn't test it on all CRTC versions.

Snowstrike shows badly on some CRTCs but fine on others. It's bad rupture code. The rupture code relies on exact timing and often the programmer didn't understand how to make it compatible with all CRTCs.

[SyX]

For Thunderblade and Druid 2 is just as @arnoldemu says, those games are not running to 50 Hz.

In the case of Thunder Blade, i remember that in 80s i had to modify the V-Hold for getting an stable image. For Druid 2 i must have in the old HD a 50 Hz patched version that i made, because the game runs between 47-49 Hz and my CRT TV hate that.