No sync using composite on PVM

[AndehX]

I have an odd issue here. Im using a PVM-20N6E and up until now, I've only used RGBs which works fine as it should.
But I just picked up a composite cable for my PSP and connected it to Line A (using BNC to RCA adapter) and im getting no sync. Nothing happens. Almost as if never plugged anything in.
Now the interesting thing is that the passthrough is connected to my XRGB-Mini and im getting a clear image on that, so the PSP's composite signal is definitely getting through to the PVM. It's just not displaying on the PVM's screen.
I tried Line B, and that works fine. Perfect image, but Line A will not display anything on the PVM screen. I would just use Line B, but it doesn't have a passthrough like Line A does, so I wouldn't be able to connect it to my XRGB-Mini for video capture. The s-video port on Line A also functions normally. No issues with that.

Here is whats displayed:
Note: 451D seems to alternate between 451 and 453. Back and forth.

[Fudoh]

On a BVM this would be solved using the internal/external sync switch. If you've used RGBs on this port before the monitor would likely expect external sync. Component, s-video, composite and RGsB use internal sync though.

[AndehX]

Yeah, the only sync settings on this PVM are external, and sync on green. And these are only available on the RGB channel. Theres no sync options on Lines A and B which are composite and svideo only. Like I say, Line B works fine, and the passthrough on Line A seems to pass the signal through to my XRGB-Mini with no issues. I just can't get an image to display on the PVM screen through Line A

[mvsfan]

I have a pvm-14n6u, and i get no sync on s-video with the ps1 i just bought. it is the only console that does this to me.
the playstation s-video works fine on my wega tv though. mabeye the psp is a similar design. they probably both need an lm1881.

[AndehX]

I have a pvm-14n6u, and i get no sync on s-video with the ps1 i just bought. it is the only console that does this to me.
the playstation s-video works fine on my wega tv though. mabeye the psp is a similar design. they probably both need an lm1881.

Yeah, but why does it work on Line B though? And why would it pass the signal through no problem?

[Fudoh]

you cannot use a lm1881 on a composite video signal. The LM1881 would delete the actual image signal and just leave clean sync....

[AndehX]

nobody have any idea what could be causing this issue?

[rugdoctor]

could it be a PAL / NTSC issue?

[AndehX]

could it be a PAL / NTSC issue?

Nah, the PVM automatically detects the PAL / NTSC signal.

[AndehX]

Ok so, so I just went ahead and got an svideo cable for my PSP, which seems to work fine. Guess I'll just have to accept a broken composite port.