Are both devices from the UK? The reason I asked is because I moved from the UK to Canada before HDMI became a thing and we had to deal with PAL and NTSC signals - my DVD player wouldn't work in Canada until I got a PAL to NTSC converter to connect it to the TV.
Is your Play Station 2 PAL (UK) or NTSC (American)? The Spectrum +2 is (I would assume) PAL.
I'm reaching, but if your PS2 is American and thus already NTSC and works, then your converter may be expecting an NTSC input. If you convert the PAL to NTSC before feeding it into the HDMI converter, it should in theory work.
Back then, a lot of the TVs had frequency and vertical and horizontal hold dials. There was a fair amount of leeway in tuning the device to display the picture consistently.
I would assume nothing needed to be exact because you could fine tune on the fly. I remember when you tuned our 3 TV stations in the UK by dialing the frequency dial to the correct radio frequency. It's been a long time that I don't recall the radio frequencies by perhaps I recall ITV being 68 MHz(?)
Is your Play Station 2 PAL (UK) or NTSC (American)? The Spectrum +2 is (I would assume) PAL.
I'm reaching, but if your PS2 is American and thus already NTSC and works, then your converter may be expecting an NTSC input. If you convert the PAL to NTSC before feeding it into the HDMI converter, it should in theory work.