Help! HTC DNA going crazy.

[PYT1125]

I don't know if it is just mine or all HTC DNAs. This is my first Android phone. I really need help with a couple problems, or it is nearly useless.

First, the battery life is unbelievable short, and it seems to get shorter and shorter over time. Now it won't even last half a day EVEN WHEN I DO NOT USE IT AT ALL. It can last for 6 hours when lucky. Sometimes it dies in 4 hours. No difference whether I turn the wifi on or off. I have considered the possibility of virus or malware, so I recently downloaded Lookout Mobile Security, and the scan told me that everything was safe. Is there anyway to fix this problem? I find myself not trusting my phone when going out because I will never know when it will die and I won't happen to be able to recharge it.

Another problem is, the screen turns on and bright on its own frequently. (This might be the reason why the battery life is so short. I don't know.) It can "flash" up to five times in a minute, although it can remain off for thirty minutes at times. Not only this problem is a concern for battery life, but also it is very disturbing at night / in the dark. I tried to look for settings to change this issue, and it is unsuccessful so far. The only way to keep it from "flash" unexpectedly is to shut down the phone completely. That is not a practical solution.

I will really appreciate anyone who can help!

Thanks!