|Which Asus model is it? |
ATX mboards are always being powered in some places, even when the computer is not running, as long as the PS is connected, the PS is switched on, if it has a switch, and the PS is receiving live AC.
You, and the person before you, MUST unplug the PS, or switch off the AC power to the PS, whenever you/ he fiddle(s) with any connection or component on the mboard.
Did you or he do that at ALL times? If you or he did NOT, things can be damaged!
Are you SURE the mboard supports the cpu that was installed ? Check the cpu compatibilty list for the mboard model.
If it is listed, usually there too is which minimum bios version is required to support it - if you look that up in the bios downloads and it's recent, e.g. within the last 6 months or so, the bios version that the mboard has may not be new enough to recognize it, and you may need to install a cpu the bios does recognize temporarily, and flash the bios, then install the more recent cpu.
" the problem turned out to be whoever fixed the new heatsink/fan to the cpu (plate in bottom of mobo ) caused the short as the plate hit the bottom of the case"
The plate on the bottom side of the mboard under the cpu socket touching the metal case or any screws attached to it touching the case would probably not cause a short - the plate is probably grounded to the mboard's ground, or not connected to anything else electrically at all.
If something else on the mboard touched the case, that may have fried the mboard, and/or damaged ther power supply. Damaged power supplies often partially work, and may pass the paper clip test, yet won't allow the mboard to fully boot.
Make sure everything that should be connected is connected to the mboard. Make sure the power switch wires and other connections on the front panel header are connected to the right pins - don't rely on markings on the mboard, they can be confusing - consult the mboard manual. Recent mboards must have an additional power connection from the PS to the mboard, as well as the main 24 "pin" one. Make sure the the 24 "pin" one is all the way down in it's socket, and the wires close to it are more or less perpendiclar to the socket rather than being on an angle.
Some Asus mboard have firewire headers, and if this one does, they are identical to the two port USB headers. MAKE SURE in that case that the USB wiring, e.g. to front case ports, is connected to a USB header - see the mboard manual. Usually the two types of headers have different colors within where the pins are. If USB wiring is connected a firewire header, or visa versa, nothing bad happens if nothing is plugged into the port, but when something IS plugged into the mis-wired port, all hell breaks loose!, and the mboard and whatever is plugged into the port will be damaged in a very short time, AND the mboard may also be damaged !
Make sure the ram is all the way down in the slots and in the right doirection - the latches on both ends should easily latch into the module(s). Sometimes you need to remove it, install it again to get it to connect properly, more likely if it has heat sinks/spreaders on it.
A frequent mistake people make these days is to install incompatible ram - in the worst cases of incompatibilty, the mboard WILL NOT BOOT, and it often does not beep either.
It is easy to test for incompatible ram, or a poor ram connection to the slot(s) problem, that has caused your mboard to fail to boot.
Make sure you have a speaker or speakers or the equivalent connected to the mboard so you can hear mboard beeps (see your mboard manual if you need to).
Remove the AC power to the case/power supply.
Remove all the ram.
Restore AC power.
Try to boot.
If nothing else is wrong, you will get no video but you will hear a pattern of beeps that indicate no ram is installed, or a ram problem.
E.g. for an Award bios or a bios based on one, that's often a beep of about a half second, silence for a half second, a beep of about a half second, silence for a half second, continuously.