MB batt

I removed ,cleaned and replaced the batt on the MB. The small one ,size of a quarter,plus side up.    Now I don't have mouse or KB and monitor is black.
No flicker of lite at all.  My pc is a Dell optiplex G1.

How exactly did you clean the CMOS battery?

While cleaning it and inserting and removing the battery were you aware of ESD and did you ground yourself?
http://www.computerhope.com/esd.htm

Finally, what was the initial reason you were cleaning your battery?

[Moderator]

Also check to dee if it's in upside down...normally it's flat side up///so the writing can be seen.

I did make sure the static elect was discharged from me and I cleaned it with a soft dry cloth and it was put back with + up. I removed it as part of cleaning everything I could pull out. It all started when someone,don't know who switched to 230watts and tried to boot. I put it on 115watts and began to try to get it to boot. I haven't got there yet. I did test the power supply with a tester and all green lites were on. I have a fan running over the processor but the fan on the power supply isn't running.
I have pulled the HDD and put it in another PC and it is good.
What did I mess up or wipe out when I pulled batt to clean. BIOS or WHAT??    johnn

[Moderator]

switched to 230watts and tried to boot.

Not a good thing.
Try unplugging the PSU from the wall outlet. Flip the rear power switch a few times. Wait 10 minutea and hook it up again.
Hopefully you haven't fried that MBoard...

If it fried the MB ,why is the fan over the processor running ? If one thing on MB goes out ,does all go out ?  I'm not that smart on PCS. If I was I wouldn't have removed the MBbatt,right ?  Anyway I have no mouse,KB or monitor so I can't see to get help or do anything. I can only pull and replace until something lites on.  Help!!     johnn

Unfortunately it could be a few things. If I had to guess, I'd first assume something has gone wrong with the motherboard.

Before following the first steps since you were recently in the computer, verify all your connections are still tight. It could be possible that while you were in you simply disconnected something or something is not connected properly causing it not to boot.

If connections look good I'd go through the basic POST trouble shooting since the computer is not beeping or booting something with the hardware is likely bad and you'll need to determine what that is.

POST troubleshooting steps:
http://www.computerhope.com/issues/ch000607.htm

[R.I.P.]

SWAG.............

Somehow I see this as a computer you added a Video card to and when you removed the Battery the CMOS reset to defaults.So,I would try removing the add-on video card and hooking the monitor up to the
on board video outlet.Then, you will have to disable onboard video in the BIOS,shut down and reinsert your add-on video card.

Well,I could be right!!!!

Thanks ,I'll try that.