in the other thread
CrazeD suggested youll try other graphic card/ram and you said you did,what exactly did you mean? that you tried both or just one of em and if just one what was it? , as for the last question yeah it can still be the mobo
check for bad capacitors and better use a flashlight , see examples
http://www.pcstats.com/articleview.cfm?articleID=195
http://home.earthlink.net/~doniteli/index27.htm
if theres bad capacitors, rma the mobo if still under warranty otherwise have em replaced at some electronic repair shop or buy a new one
if you didnt find any it doesnt rule out the mobo , try hard resetting the cmos , unplug the power cord and get the battery out for
1 hour then put it back & plug the power cord & power up , its important to put it back exactly the way it was and not upside down , if that didnt work then get all ram sticks out and power up , usally a good mobo will beep when theres no ram..
if you meant ^ that you tried a diffrent graphic card then it defintly cant be it , its more likely the mobo or psu
edit if the capacitors are fine & resettings the cmos didnt work & it beeps with no ram then get a digital multimeter (their pretty cheap) , set to 20 DCV (Direct Current Voltage) , measure the psu voltages with it and report back , see these guides
http://www.ochardware.com/articles/psuvolt/psuvolt.html
http://www.driverheaven.net/guides/testingPSU/