@ VCR gang : thanks for all for your feedback. Problem solved..indeed nothing wrong with my video composite signal, was the bloody LCD TV that fails to deal with it somehow
It's a TV not a computer screen. It's made to receive TV, both analog and DVB, so you would think its SCART would work with a VCR wouldn't you ? A TV with SCART... what else are going to connect it to, other than A VCR ?!
If it fails to work with a VCR then both SCART and composite then... well it's useless to me, as I won't trust it to display other potential sources of composite like vintage computers or a camera or test gear or what have you. It also has a built-in DVD player with dedicated control buttons... player does not work either, it's kaput. OK.... this TV monitor is going to be taken apart and scrapped tomorrow probably.
I got given also another TV, 32" LCD. Fails to power up. Will see if I can I fix it and will give this one a try. Does not have composite but has SCART.
Anyway. At first I tried with a 75 ohms termination : I found another composite cable, so I could connect the VCR to both the scope and TV at the same time. Of course no picture on the TV but I didn't care, all I wanted is to plug the cable to the TV so that it gets connected to a proper 75ohm load. Then I would at the same time scope the signal, in high-impedance, so I could "spy" the signal without affecting it.
It worked, signal amplitude was not about 1.0Vpp which is correct IIRC.
Didn't know that the sync pulses were hard coded into the tape itself ! Thought they were added by some IC on the main board afterwards... OK so cleaning the head could help there as well then. So I gave that a try. Cleaned the heads/drum with some IPA. Looks clean and shiny but still managed to removed some black stuff on a couple Q-tips. Signla on the scope now looked much better, stable, cleaner, not all randomly going haywire violently as it did in the video I posted yesterday. Not signal is solid, cool. Still no joy with the LCD TV though...
Only old analog CRT monitor I had, was a tiny portable " CCTV " Sony Trinitron, with a BNC socket as an input. Tried that before cleaning the head, got something but just garbage, like sync problem : pattern of alternating black and white 5mm think horizontal lines, tilted a bit to the right. After cleaning the heads, I get a good picture !!
Input can be switched to SECAM or PAL. It's SECAM here. I get a good picture either in PAL or SECAM, it's just that in PAL mode, I get a blank and white picture, but still a good/valid picture. One of you did mention that IIRC.
OK so I can button up this VCR and keep it handy, I know it works now. And I now also know that these LCD monitors with a SCART and composite inputs are just useless pieces of shit that can't be trusted, rendering them useless. If you have to pray every time, hoping they would be kind enough to work whatever piece of equipment you might want to connect them to... then I don't see the point. Either it works and you can trust them, or it does not
Anyway, need to fix that other LCD TV to see if it works better.