Hi my name is ***** ***** I will be the expert working with you today to help and resolve the problem you have posted.
I am sorry to hear that you are having such trouble. I will try my best to help you out and resolve the problem as quick as possible.
How old is the player?
If you have opened the casing and its just 2 months old the warranty is a bad now, however to detect the tray issue can you check the tray mechanism does it have a rubber band like belt on it pulley gear.
try to locate at the bottom there must be a rubber belt which might be broken or worn off.
you will see there are few cables connected to the main board try to unplug and cables and re plug it back and then check if the problem persists that means the open/close tray sensor is bad.
I am online now.
If you have tried all the steps i suggested and the problem still persists then its the problem with the main motherboard. I thing you have opened the casing and the unit is still under warranty if the warrant sticker is not damaged then you can contact the manufacturer and get the unit replaced.
let me open the question to other experts for there view as i am out of ideas.