High temp no fan

[tony6264]

I have this A21E that is acting wierd..it seems that when it is cool and been off long time it will run fine....then out of nowhere it will start acting up and not boot properly till the next day. I have tried listening for the fan and I dont hear it..also when it acts up it acts like the cmos battery is dead, even though I have installed a new one.I have to keep resetting the date and time and sometimes it will lock up before I get a chance to reset them both. Will a bad or going bad fan cause this behavior? I am tempted to swap it out with another fan I have and try that. I have even gone so far as to put on a temp sensing software program to see if it will tell me the temp. Is it more likely the fan is bad or going bad or is it the motherboard not letting the fan run.
any ideas please?