@Roman Nartov
Siglent Techical support engineer looked at your post and replied to me:
Hi Rob,
For this problem.
Our suggestion is same like you .
Best regards,
Jexy
Please see these examples of a similar LCD problem and how it was fixed:
I plucked the silicon off the LCD Mylar flexcable that goes directly to the LCD and reseated the cable, booted up the scope and the display is now back to normal see the pic. There you have it the cable socket is a hinged type that lifts off the cable as I discovered under the silicon adhesive so any contraction of the silicon over time is going to reduce conductivity of the cable to socket as it would have a tendancy to unlock the cable.
The silicon I'm referring to is on the small PCB stuck to the back of the LCD panel which has two connectors one is the end of the ribbon cable coming from the main PCB and the other is a socket for the Mylar (clear orange) flexcable which goes into the TFT display itself. This small PCB looks to be a bridge between the grey ribbon cable and the orange Mylar flexcable. The problem had nothing to do with the grey ribbon cables.
There's no tape on any of my cables. There appears to be copious amounts of white (neutral core) silicon used. Quite a bit of it around the legs of a group of electrolytics on the Power Supply board (probably for HV insulation). I know this stuff shrinks with age and realistically I can see why this would cause a problem on the specific socket due to the construction. Once you pick off the silicon the socket latch comes away at 90deg to the cable, it's the hinged variety. I didn't get a pic of this as the scope is all sealed up now.
There's a possibility this will occur with other units. Very strange how the display was reversed though.
Anyhow I thank you all for the suggestions.
Bigfoot.
It seems the white silicon rather than preventing connection problems on the
LCD mylar connection is actually causing a connection problem by way of shrinkage, partially pulling the connection apart.
This is maybe something Siglent needs to address with a different more stable product.
Please report your findings to us.