Unable to connect to my Vostro 5460 bluetooth

Hi,

I had bought this Vostro 5460 less than 2 weeks, and while i try to connect my mobile via bluetooth to the laptop, i get error message unable to connect shown in my mobile. I did try to paired the laptop and mobile devices, after i key in the same code in my mobile when i got the pairing request from the laptop, its successful to paired but failed to connect. I can see my mobile device shown on my PC Setting (Devices). I am able to send file from the laptop to mobile, but i am not able to send file from the mobile to laptop as its keep showing "unable to connect".

FYI, due to space bar and touch pad issue, i had requested to change the keyboard. Hence, all the parts had been taken out and re-installed before. I am not sure will this cause any issue.

Would you please advise?