Can a spent CMOS battery interfere with a startup on an iMac?

I have an iMac that doesn't start up, neither from any bootable usb device, bootable CD etc (you can see the startup manager icons and you when you click one you see the progress bar but it stops there.

The Apple troubleshooting procedure (GSX service guide) advices me to check that the motherboard battery isn't spent, the reason why I ignore. Can the CMOS memory hold some setting that may halt the startup???

PLEASE ANSWER TO WHAT I ASKED, I DON'T NEED YOU TO HELP ME TROUBLESHOOT THIS IMAC, JUST TO KNOW IF THE CMOS MEMORY COULD STOP A STARTUP AND WHY.
ALTHOUGH I'D WELCOME ANY TROUBLESHOOTING SUGGESTIONS, THANK YOU