Dead Acer Notebook

I have an Acer notebook which has suddenly developed a case of intermittent startups.

Without battery attached, it will sometimes startup…but then lock. It will get into safe mode ok.

When I restart, it just dies. Pressing the on button does nothing. Releasing the battery and trying again after an hour will get it to start…but then it just locks up.

Could it be the CMOS battery, which, of course, I can’t find underneath any of the panels, or perhaps the cpu fan is burnt up?

Any ideas would be helpful.

Thanks.