Droid Razr randomly dies and sometimes wont turn on.

[mrdylanspencer]

OK so I know this is probably like a lot of RAZR threads but my scenario is different than others I have read about. I have an original Droid RAZR running stock JB.It is rooted. About three times a day at random intervals, it will just die. Black screen... completely powerless without warning. i can usually turn it right back on and continue but sometimes it wil not do anything unless i plug it into the charger. in this case, it will boot but if unplug the cord while its booting, it dies again and wont turn back on. i have tried every button combination i can think of when this happens to no avail. any help will be much appretiated.
if it means anything, i am a nube with anything rooting. i can underclock and freeze apps and thats abot it. also, the phone had Boot Menu Manager on it when i got it but i removed it.

Also if it means anything, I have no Sim card inserted. I just got the phone and still have to get one. Maybe this has something to do with it.