When I push the power button there is a sound of the fan, the keyboard lights turn on and there is no Dell sign on the screen. I have to turn off the computer and try one or more times.
Afterwards there are no problems with using the laptop.
I tried to replace the Ram, HDD but without changes.
I also changed the Motherboard battery.
Any suggestions how can I solve this problem?
System Windows 7
Unplug the system, remove the battery and hold the power button for 30 sec. Try powering up on AC only -- no battery. If the system will power up that way, the battery is bad - replace it.
If the system still won't power up reliably, replace the mainboard.
That leaves the mainboard as the faulty part -- if you have intermittent powerup problems, it's likely there's a cold solder joint somewhere on the mainboard going bad.