Hi,
I can see it connects to the printer and receives a few responses from printer but nothing after sending M105. I can connect to the printer with no problem using Repetier Host.
Hmm.. that's a pretty standard command to send. No idea why your firmware wouldn't respond to that. Have you tried manually sending an M105 command through another serial program like the Arduino serial monitor? Pretty much every firmware that I have used is capable of responding to an M105.
You also didn't mention what firmware and what printer you are using, so that would be useful to know in addition to the test above