Hi Marius
I had a similar issue with one of my CS2s: a thin flexible PCB going out of the display and pressed by a pressure connector.
A bad contact does this in my case
Here are some pictures
The colour display with its touch screen

Notice the top cable on top which is the display data, the cable on the lower right which is the touch screen data and the lower left cable which is for LED backlight
The cable that is very sensitive is the display data cable and it goes into a special connector to which you slide open (one mm or so, caution it is fragile) and then you can slide out the data display cable, clean it (contact spray with a paper tissue wiping from the cable toward the extremity, NEVER in the other direction).

The connector and the mother board (CS2 60215)

In the red frame - Top area-, notice the connector in 2 parts:
- the beige large part which is soldered to the PCB
- the brown part which is the latch that move away (one mm or so) from the beige part to unlatch the flexible cable
On the lower area, notice the rectangular hole through which the display data cable goes through the PCB.

Of course your ECOS will have a different PCB (mother board) but chances are the colour display (same size and probably the same definition as on the CS2) will have a similar / identical connection.
I hope this helps
Cheers
Jean

Thank you to John and Dave (emailed) for your advice.
I disassembled the unit, cleaned the ends of the wiring ribbons with pure alcohol and re-assembled everything.
Problem solved; the display is now looking like it’s supposed to.

For interest I have added a picture if the mother boar showing the ribbon and power connections to the touch pad & screen.