hp 070 projector bulb goes out after about 10 mins?

Ive got a chinese hp 070 projector and i thought the bulb had gone so replaced it. It had got quite hot as it was close to my fire but it didnt stop working then it was the next time i used it it came on for about 10 mins then the bulb went out so i got a new bulb and the same happened any ideas anyone.
Dont know maybe its some software problem som one told me it could be the firmware?