What is the make and model of the laptop, how old?
What was the purpose of getting into the laptop?
Were any cables disconnected, were they properly reconnected?
The laptop is the Hp pavillion Dv6 6c41sa , it is only about 3 years old at max. i had to open it since it was reaching very high temperatures, I'm talking 83 degrees Celsius i was sure it would over heat. so i wiped off the old thermal compund on apu and gpu (duel gpu laptop), reapplyed thermal compound and thought ill test it disasembled it worked great id taken it down to about 27 degrees on idle from like 83 a good job but id notice when the fan was not trying to breath air from any case the noice was un audable so where i saw normal i cut a small hole where the fan goes this would mean that the fan gets fresh air and would be quiet i added mesh also. then i assembled it and it would not boot nothing , so i disasembled it again and tested it worked fine i thought it must not be grounded propally ill test after each couple of screws i put in , i did after taking apart alot and assembling due to it keep not booting i had done it , i only needed to put the wifi module back in good so i though, i put the wifi module back in and it would not boot so i removed the wifi module would not boot took that out would not boot took a few scews out partial sucess it booted a couple of times then i removed the mesh thinking it would help incase of that doing something to the grounding , i removed it it booted , then i decided lets reboot it would not boot by now i was pretty annoyed .
but i kept going i was like ok i cant get it to boot at all now ill take the board out and try it without the case and i can tell you now i havent got it to boot for over a week , i try every couple of days it does not work just a flashing light at power port no fan spin no screen cant power it on just nothing with battery and charger only shows flashing light at the power port i do not know what to do . im a genius and have built my own gaming pc but this is beyond me i have tried connecting and disconnecting cables incase i had not pushed them enough i had done everything right