Did a little more checking - didn't really discover any revelations but hey...
BASIC is definitely working. I blindly entered
10 BEEP
20 GOTO 10
RUN
and got a continuous beep until I pressed stop. Cool. My first MSX program and I didn't even see it.
The mainboard -> PAL encoder connector (PAL1) has the following voltages on its pins:
0v (maybe a millvolt or two over), 4.7v, 2.46v, 3.01v, 2.58v, 0v
The output from the PAL encoder circuit (PAL2) displays only a millivolt or two over 0 on both of its two pins. So basically, there's no PAL encoded composite signal from that circuit. Struggling to check what's happening on LVA510 itself because I don't know what the pins are supposed to be.
I can't say for certain which TMS99xxx is in there. There seems to be something glued over the top. 
But I'm reasonably convinced that the European HX-10s used a TMS9929A with YPbPr (ish?) output.
Here's a photo - not that it helps with anything mind.
Hi folks!
Actually, I have downloaded the TMS99x8A from somewhere on the internet... And it says that on TMS9918A chip you have CVBS on pin 36, but if your HX-10 uses an TMS9928A/9929A you will get Luma (Y) on pin 36. So, regardless the version of the VDP your MSX uses, you will get video (BW or NTSC colored) on pin 36. You have to be extra-careful here, because pin 37 is an clock pin, and it's not rare at all to have the VDP output clock damaged, and the MSX won't boot anymore after this (until you change the VDP or install any "Z80 turbo kit")
Anyway, is more likely your MSX have an bad encoder IC than an bad VDP. Or any faulty capacitor in between those two.
If you're planning to mod your MSX to get component video directly from VDP, I recommend you studying both HX-10 schematics and TMS99x8A datasheet, because you need some small circuitry after the VDP pins that could be already on the HX-10 mainboard (like my Sharp/Epcom HB-8000). But a friend of mine told me a sec. ago that some modern TV sets cannot handle component video with less than 480i lines... Still, it's worth a try. (just try don't shorting anything on your VDP! 
)
What HX-10 schematics? 
By checking where pins 35 and 38 of the VDP go, it should be easy to tell TMS9918A and TMS9928/9 apart. But I bet it's one of the latter, since with a TMS9918A that PAL encoder IC would have no function.
If a simple component replacement doesn't do it, designing / adding some other circuit to pull video from this MSX1, is not worth the trouble IMHO.
Here's a photo - not that it helps with anything mind.
Hi, from the photo, in the right-bottom part i see clearly a chip labeled "GIxxxxxx" this is the PSG.Above this there is a toshiba labeled IC that i suspect is the infamous "VDP clone" by toshiba. If this is true, you must find the correct datasheet for this VDP, that is different from the Texas Versions. (I'm not sure however)
Morning,
But a friend of mine told me a sec. ago that some modern TV sets cannot handle component video with less than 480i lines...
Ah of course - I thought things were sounding too easy for a second there. 
i suspect is the infamous "VDP clone" by toshiba. If this is true, you must find the correct datasheet for this VDP, that is different from the Texas Versions. (I'm not sure however)
I'm not sure to be honest (but I'll check). The original photo I took isn't big enough to zoom in so will take a peek at the chip when I get home. Everything I've read says that Toshiba used their own VDP on the HX-20/22 but a Texas TMS9929A on the HX-10.
@Retro - you're probably right about it not being worth the effort. But no doubt I'll end up taking this on anyway... :D
Apparently this is a Toshiba HX-20 with the T6950 visible in the top left
