I have a defective switch item , which boots, touscreen is working, keys are working but there is no picture. Water indicator is red but I cannot see any liquid damage.
As everything was working but the LCD I changed the digitizer and LCD with a new one, but still no backlight / no picture.
Now I am running out of ideas where the problem can come from as I was quite sure that with a new LCD it must work 
Any ideas what I can do to fix it ?
Looking at the connector from the battery to the left button mainboard might be damaged, but not sure - also if this can cause such problems…
Your cable seems to have a bad line in the yellow circuit (line6 from right). That goes to the 2nd line(yellow one) count from top on the Backlight cable connector on the daughter board.
Check with mulitimeter with extension cable connected, see if you have continuity beep (measure from the cap right side, to the backlight connector 2nd pin from top)
Thanks for you quick answer and help!
Have tried with the multimeter and there is no continuity beep (hopefully I did it right) - and after further inspection line 6 seems to be definitly broken.
I have ordered a new cable whoch could take a while to test if this works after that. If (only) the cable is the problem then it should be fixable.
Think I cannot do too much in between… ?
Though I would carefully inspect the connector also for charring, as they do typically need to be replaced in those events.
definitely agree with this as well, the last 2 water-damaged switch lite that I fixed are damaged on the 18V(?) backlight line ( Check Main board FPC > Daughter Board FPC > Backlight ribbon cable for damage). If you are lazy you could just buy the daughter board now from ali ($20) if you are dead sure the problem is on the daughter board, or else you would have to buy the FPC connector ($12 for 5) to replace it on the mainboard side.
Can always double check the LCD FPC Connector.
Today in installed the new cable and display is working again - so thanks for the support
