Head unit probs

[Patnnad]

I have a Alpine Double Din IVA-W202E head unit. I installed it myself and it was working fine for 4 months then out of nowhere it started playin up. When i power it on, the power last anywhere from 2 seconds to 2 minutes. Then it shuts off. 5 seconds later itll let me turn it back on but it just shuts off again.
Ive had my mate, an installer, have a look at the wiring and he said it was all good and fixed up anything i had wrong. But its still playin up.
We concluded that it was the head unit itself but i wanted a third opinion.
Any help

[Patnnad]

Forgot to mention its fitted in a vx berlina wagon

[holdenboy]

Well yeah, if a pro installer looked over it and couldnt find any problems then its gotta be a unit fault.