Installed new cpu and pc whont boot

[tony0600]

I had pentium 4 2.8ghz 1core soo installed a 2.5 duel core it booted fine 1s try but was runing at 1.7ghz soo i go bios and set dafult and set whet 2.5 but now it whont boot at all i try enter bios but pc just restarts i disconected the batery to try reset bios but not having any luck

GIGABYTE GA-G41M-ES2L LGA 775 motherboard
Intel Pentium E5200 Wolfdale 2.5GHz 2MB L2 Cache LGA 775
G.SKILL 2GB 240-Pin DDR2 SDRAM DDR2 800 (PC2 6400)

 

[boonality]

When you say running at 1.7, was Speed Step on by chance?

 

[tony0600]

it was set by default at 1.7 but the cpu is 2.5ghz

 

[boonality]

I know what your trying to say. What I mean is that it could be because of Speed Step, in othe words, it is supposed to be at 1.7GHz when idle.

 

[tony0600]

the thing is i set it default now i can even acces bios setup it just plain restarts i tried using old cpu and does the same

 

[tony0600]

its not psu eathier since i tried it on another system i also tried swaping ram and no luck

 

[jsc]

Our standard checklist and troubleshooting thread:
http://www.tomshardware.com/forum/261145-31-read-posting-boot-problems

 

[tony0600]

was waroking fine with that old pentetium 4 2.8 ghz once i put in the 2.5ghz duelcore it work fine but was runin at 1.7 ghz and no 2.5ghz soo i whent too bios and set dafault 2.5ghz now i can even enter bios pc just reestarts