|Dusty, usually the internals of the PC tower are fairly straight forward to piece together. Basically if something doesn't fit somewhere it doesn't belong. |
Usually a flat CMOS button battery will just revert the BIOS to its default settings but the PC will still power up normally. A giveaway is the date is reverted back to the BIOS's manufacture date. But unfortunately you don't have a screen image to factor this out right now.
I'm assuming there aren't any beeps when you power the PC up?
Do you have multiple slots for the RAM? And do you have more than one stick?
Disconnect the power completely from the tower and try inserting just one stick of RAM in the slot closest to the centre of the board. Power on and see if you can successfully get the computer to start.
Also are the graphics integrated or do you have a graphics card installed that you run the monitor off? If you have a graphics card try reseating it. Also if the motherboard has a graphics port you could try using that instead for troubleshooting purposes.