I heard Marine Max conducts repairs on LCD panels like this. Furuno service center won't repair them, we replace the entire panel which about the first 1.25" of the unit. If the touch works would normally depends on if it is dis-bonding or delamination because there is a difference. I don't think I have ever saw delamination of the touch matrix but I have seen dis-bonding internally of the LCD to the glass. Disbonding normally won't change the touch functions.
When LCD panels are made for the marine environment, they are either bonded or not bonded. The inherent challenge is non-bonded panels have a chance of condensation and bonded panels have the chance of dis-bonding. This is a challenge for all manufacturers and a fact for all involved. Navico, Garmin, and all others have seen issues with both methods, as have we. Tesla for example has seen dis-bonding with their navigation panels in cars. There are many variables that impact both methods and how long each will last (heat, sunlight, moisture, hot to cold to quickly or vice versa, customer care, etc).
From what I understand repairs run about $600 and come with a 90day warranty (via whomever). The Furuno USA service center is running a program right now on the TZT14 where entire LCD front panel is replaced with new for $1115.00 plus shipping. The new panel would come with a two year warranty with the service center.
I don't know what you mean by sync issue. Do you mean NN3D power sync?