Display won't turn on after a repaste

My Asus G750JS laptop was heating up a lot after 3 years of usage, so I disassembled, cleaned the fans, CPU/GPU and repasted both of them. After I reassembled, the screen won't turn on. It was working perfectly fine before the disassembly. I had even overclocked it to 95hz (from 60hz). Things I have done :

* Connect the laptop to an external monitor through VGA (it works, GPUs are fine)
* Hold the power button for 2 minutes to discharge then plug to AC and power up
* Disassemble the laptop and unplug/plug the connector several times
* Blow the connector with a duster and then try
* Clean the connector with rubber eraser and alcohol and then try
* Weird thing - when I unplug the connector and try to boot with only the external monitor connected, the external monitor doesn't work.
* When I close the lid the laptop DOES go to sleep.
* I've checked the device manager and the monitor is there. Both monitors are named Generic PnP Monitor

 

Your internal LCD is connected by a ribbon cable. these are very delicate. Be sure it is clean and dry with an eraser. Be sure it is inserted fully back in and seated properly. If that is all done it is possible the cable got damaged and needs replacement.

 

Thanks for the answer. Yes, I have cleaned the connector with alcohol and an eraser. I'll do it again to make sure, but I was very gentle with the cable (and everything else), therefore it is hard for me to believe that the cable is that delicate.

 

I had one laptop that took 3 reinsertions to get a proper seat, be sure it is always all the way in and be gentle with the clamp down but be sure it is seated as well.

 

Seated it again, and again, and again. Cleaned 3 times. Nothing seems to work :/

 

Not sure then what happened other than the inverter has gone out. Try a good flashlight up against the screen while and after post to see if just the backlight went out too. since the external does not work with the cable unplugged it seems it does register something allowing a post.

 

Yes, I have tried that as well, but nothing shows. I have no idea what the laptop is registering to let the external monitor work.

 

The question is: were you wearing a ground strap? Did you ground yourself out several times throughout the process of handling all your components if not wearing a ground strap? Did you use a vacuum to clean stuff (big no no).

Not booting at all when leaving stock lcd panel disconnected is normal and means your hardware can't fully initialize so your BIOS isn't posting and preventing your computer from finishing it's boot sequence as mentioned above.

It sounds like you have a faulty cable connection somewhere or partially blown electronics. If you really wanted to dive deeper into troubleshooting your lcd panel you can go grab the schematics and data sheet over on panelook.com and break out your multimeter (requires fine tipped probes) and get to checking the pinout connections for power, ground, etc... But that will only get you so far.

 

No, I wasn't using any straps and in fact, that's what the guy I called today (an expert in repairs) asked me as well. And no I didn't use a vacuum, I used canned air to blow the dust. I think I'll be taking the laptop to him because when I disassembled the display itself today, the laptop shut down suddenly (it was on, connected to an external monitor(I know it is silly)) and now it doesn't power on while connected to AC. Powers on fine with the battery on though. Display still doesn't work, it's probably the cable. I'll update after the repair.