Is there a speaker connected to the mainboard? Did you used to get a post beep before?
I would recommend a bench test, remove the mainboard from the computer case, leave cpu, cpu cooler, 1 stick of ram in 1 slot, the video card (if you have onboard use that only), and then connect the power supply only to the 20/24 pin and 4 pin. Try to power it on this way. If you can not remove it from the case, disconnect all case usb/audio headers and remove all components from the main board that are not needed: hard drives, disc drives, add in pci/pci-e cards etc. Visually inspect all usb ports for damaged or shorted pins etc. Reset cmos, either remove the power cord and the motherboard battery, or use the clear cmos jumper.
By rework I assume you heated the chip up or "reflowed" it. This can sometimes fail, I am not sure how you did this but if the chip was overheated extensively it may be done completely. If none of the above methods work, you will need to replace 1 component at a time. I usually try in this order: different ram (1 stick tried in all slots), new psu, different cpu (most of the time these are cheaper than boards), then lastly a new board. Of course if you have already ruled some hardware out as it seems you have or happen to have a different board but not other components you can test in any order you would like.
You only need 4 pieces of the puzzle to get a full post: cpu/cpu cooler, ram, mainboard, psu (plugged into the 20/24pin and 4pin). Connect a monitor (no mouse or keyboard at this point) and power on by shorting the power button pins (where the power button connects to the mainboard) you will not damage the mainboard by shorting the power button pins as this is exactly what the power button does.
Edited by zingo156, 12 March 2014 - 12:34 PM.