[Ham-Mac] eMac Came On, Clock Not Correct

[Brian Short]

Interestingly, after sitting in my living room
over night, the eMac powered on after which
I ejected the MicroHam CD, and shut it down.

It was cool here yesterday as it is today.
I blew out the back and cleaned the eMac.
It is an uneasy feeling that it could stop
working again at any time.

I am wondering if it could be a fan?

How do you get an eMac open to replace
the settings battery?  There is a special
wrench for the screws?

Or, just take it to the Apple Store?

What to do?