SOLVED Toshiba D29C051 Trisync monitor and horizontal centering/sync issue

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Hello everyone !

I have a Sega NNC cabinet which has a trisync Toshiba chassis and groovymame + crt emu drivers configured with custom arcade 15-24-31 monitor settings.

I use the 31khz mode in 640x480 for the frontend and windows logging and 31khz emulators, and I use groovymame and retroarch with crt switchres for 15khz stuff.

Everything works pretty neat except one thing.

When switching from 31khz to 15khz I have this behaviour :

- Most of the time centering is ok
- 1 time / 4 the centering is shifted 2-3cm to the left always at the same position
- 1 time /10 it can be shifted pretty far like 6cm with bent image

I get this solved when I turn monitor off/on, it syncs properly at the right position.

Currently I am using a small program to turn monitor off and quickly input a key from windows and did an Autohotkey, it acts like redoing the horizontal frequency adjustment again.

I didn't always had this behaviour, something has changed in my setup recently, but I don't know why, and I would like to try to understand why horizontal centering can get randomly off.

Note the chassis had a cap kit done recently, it could be related to that but before messing with circuits, as everything else work perfectly, I would like to have your opinion with this.

Also Retroarch's CRT switchres don't mess with the horizontal centering like GM does when switching.

My theory is it sends the signal to the chassis and it doesn't enter the no signal mode before switching. I have to find some solution to make it cut the signal then switch.

It always switches right from 15khz > 31khz and always syncs right from No Signal > 15khz, the problem happens only randomly from 31khz > 15khz.

I could be wrong, it can be something else, but if you guys have a clue thanks for your help.

EDIT : Solved the problem, it was a bad capacitor in the list, it had the wrong value.