Cheap LCD screens - One works one doesnt.

Hello , hope you can help/suggest etc (or just learn from this)

I've developed a project using Arduino 1.6.6 the TVout library that works fine on larger TV screens and on a 7" car monitor on my bench, but when I came to plug into the 3.5" screen it must actually work with I get vertical ghosting, flickering and a black line near the bottom of the screen.
No problems horizontally.
The reverse camera kicks in at the on-demand channel as it should, and runs perfectly.
Code changes for NTSC and PAL made no difference.
I've even had the 7" and 3.5" running off the same output (Uno R3?) , simultaneously ...same sync issues.
With 'Pert' 's help I've updated my TVout files with the 4-month old TVout fix for modern LCD's on Github by Avamander? but still the same.

Stripping the screens down, I see the larger one uses the MST702 chip. That works fine.
The smaller screen runs a AMT630 chip, allegedly a clone of the MST703. This must be the cause?

Anyone have any coding solutions to try?

What chips do the 3.5 and 4.3 tft Arduino touch screens use I wonder? Am I missing something obvious?

Prefer a software solution if possible, as the screen still has to work with a camera on its other input.

I'm not a stranger to code, but I don't fancy analysing and cut/pasting the relevant code from TVout, TVfonts and Video_gen etc etc unless its definitely going to help me. (I believe Libraries slow it up but is that really the issue with this other chip?)

Maybe this is an old thread and I'm not searching with the right keywords (all the fluff on touch screens LCDs etc gets in the way) if so, please point me in the right direction and accept my apologies.

David.

Sorry, the TV screen is more probably LED than LCD? Some call it TFT... so I posted this again with a new tile...without the reference to LCD which will only confuse people.

Please do not post to this thread.