alpine head unit

[don82]

hi-heres a challenge for u-i have an alpine cda-9855 head unit which has been fine until today when the display kept turning off after a few secs-sound is still fine and when a button is pressed it comes back on-i know some alpines had a 'blackout' thing on them but i dont think thats it-i disconnected the unit and it was fine after-i did notice that the little fan at the back wasnt working tho-could this be it? it sometimes seems a bit warm? i had a lesser model alpine in before and when i fitted it (am a mechanic) i just swapped the small black plug at back of unit to the new one-could this be y fan doesnt work?