hp pavilion g42 black screen win7 ultimate 32bit

[Makmur_1]

hi everyone...

i have a problem with my laptop hp pavilion g42-360tx, my laptop cant show any pic (black screen) while i want to boot. it doesnt show any pic even i cant go to bios menu.
the problem appear when i want to switch hdd from my notebook hp pavilion dm1-4000mx. after i install the hdd, i choose the wrong adaptor, i plug my notebook adaptor to my laptop charging port. and the screen doesnt show any sign of image after i try to boot my laptop, but the machine still running and works (i can feel the heat).
is there any failure on my motherboard? because ive tried to press and hold the power button for 30 secs without any battery and current, but it still nothing happen after that.
and ive tried to pull out my ram and try to boot with another ram from my notebook. and also ive tried to connect to external monitor and no signal detected

please help me

 

[ffg7]

what is the voltage & amperage marked on the notebook adaptor & what is it marked on the laptop adapter even tho a notebook is a laptop & vice versa?

 

[Makmur_1]

what is the voltage & amperage marked on the notebook adaptor & what is it marked on the laptop adapter even tho a notebook is a laptop & vice versa?

the voltage on the notebook (dm1) adaptor is 18.5 V output with 65W power
while the voltage on the laptop (g42) adaptor is 19 V with 90W power. i forgot about the ampereage, but i think we can calculate it lol
is 0.5 V different can make such a bad situation?

 

[ffg7]

too many watts is ok but too many volts is not ok.

 

[Makmur_1]

too many watts is ok but too many volts is not ok.

so in my case, thats not a problem right? because my laptop voltage is 19V and i use charger with 18.5V

 

[ffg7]

not enough voltage is bad too as it is in "brownout" mode not blackout.