Could be a bad motherboard. Try removing the CMOS battery from the motherboard, unplug all power, hold in the power button for 30 seconds. Plug in the wall charger only, see if it turns on. If it does, replace the CMOS battery and see if that works.
Lcd screen might be damaged. Try hooking up hdmi or dvi port whatever it has, you need external monitor and cable. There might be also key to change video input look it up. Do what hang-the-9 said but when your disassemblying try to boot it without lcd screen cable connected, hook it up to your external monitor and boot, maybe screen is shorted also. YOu mean dv6 3200 series? These have nearly always failing GPU which is integrated