My sister just had what sounds like the exact same problem. She took out the battery and left it for a few minutes, reinserted the battery - and hey presto! Something to do with resetting the CMOS, I think.
As you have removed the CMOS battery maybe it is starting with the wrong connection.
Check again and if floppy is switched on disable it, Have it set to either run from the hard drive or the CD drive.Some times when you remove the CMOS battery the computer will try and start with the floppy drive even though it does not have one.If that's the case disable it.
The problem nothing displays . it becoming chicken and egg situation.I have try to connect to an external monitor and change for external VGA mode, boot with linux centos bootable cd but nothing displays.Press F1 Del for Bios setup but no luck. Any more sugestions