I have Compaq Presario CQ70-150EV with the following issue: suddenly one day my latop screen freeze when i was on bios (i didn't change anything). after i close my laptop (unplugged the charger because i can't do from the power button) it never boot again. Now the laptop turn on automatically as i plugged the charger into my laptop (wihout battery), without prsseing the power button. The laptop won't boot the led is on and the fan woring and i hear the dvd check, no noise (beep) sounds. Nothing appears on screen. I try the following:
1. connect to another screen
2. remove the ram and put one each time to different position
3. replace the cpu with another sam (i order one second hand)
5. replace the motherboard with another same ( i order one second hand)
can you help me? is anything i can do before i quit?
is possible the power jack have a problem. if i change it the boot problem will solve?
You have done some pretty good troubleshooting and it may bee a power jack issue, because as far as I see it, the laptop is getting enough power to spin fans but it may not be enough to boot the system.
I am concerned why is that power button not working and how is that you get the laptop starting without pressing the button. Is it stuck? If it is as constantly pressed, you will have difficulties booting.
Have you fixed it when changing the motherboard?