Sony PVM 20M4U - PS1 Composite connection issue

[Malhechor]

Hi guys, just bought a Sony PVM 20M4U, tried connecting my PAL PS1 to test only using Audio/Video cables (composite), the issue I noticed is that the initial Sony logon screen is jittery, however when playing the game (Castlevania SOTN) it seems ok. I know that composite is not the best video source, just wondering if anyone knew why the screen is jittery at start up.

Note: Tried my PAL Game Cube and same issue except that the game was also jittery (Res Evil 4)

Cheers,
Mal

[Fudoh]

480i/576i (PS1 boot screen & Cube) vs. 240p/288p (PS1 ingame)

[Malhechor]

Okay, yes I understood the boot up was at 480i but the PVM can handle that too. Also I checked the VSync and now it’s a lot better on the menu screen.
Are the any guides on the average values to use in the service menu etc for the best picture, I get lost in the menu .