hp dv5 daqt6gmb8b0 just ON and OFF

so what? where are attempts to do something?

When you decides to ask for help you always need to indicate the greatest number of details checked in your revision.

In this little time that the mainboard starts, what voltages you could find ?
Do you already checked the comunication between EC and southbridge ?
Do you already flashed the BIOS ?
Do you Already checked de clock signals ?