i have brought a sony vaio pcg-791m laptop for spares/repair i thought it is an easy fox as it said that its a blank screen i have fixed a laptop with blank screen before but this laptop seems different the symptoms are when i have the power plug in the battery light flashes im not shore if this is ok or not but when i press the on button the 3 lights at the top stay on all the time and all the light on the bottom except the battery button but when i try to shut down the laptop by pressing the on button the battery light comes on and it depends on how long i press the on button the light will come on eg if i press the power button on for 1 minute the battery light will be on for one minute at the same time what every i do the screen does not respond i tried removing hdd and ram but still nothing tried booting without battery or with still nothing and now i have no ideas what to do next so please help me
If the battery light is flashing when plugged in, that means it's charging.
Have you removed the BIOS battery and left everything unpluged for 30mins?
your bios might be corrupt. if you haven't then its worth a try
Well, ive had two laptops that has had similar problems - blank screen and all. Most of the time it comes down to a faulty motherboard. Try plugging it into a external monitor and see if anything comes up, If nothing happens - try disconnecting the laptop screen from the Motherboard; try again like that.
Be sure to take the laptop battery out and power supply & hold on button for 30seconds to empty the caps.
well i tried to put it through external monitor and pressing fn + f5 to switch but it said no signal and tried the thing with holding the power button for 30 to 60 secs but have not tried to disconnect the screen