Fenix 5X does not start

Hello,

since yesterday my Fenix 5X does not start and I see only a black screen! I tried every combination to reset the watch (soft/hard) and I connected it to my PC. Moreover I charged it for several hours.

Nothing solved the problem!

Unfortunately Garmin does not offer to repair units and they only replace it for ~200€!

Does anybody has an idea for this problem?