Black screen after BIOS change

[Innocentius_C]

Laptop is Acer 4820TG. My display won't show anything, not even the pre-BIOS screen with information.

Recently I have changed graphics mode in BIOS from switchable to discrete and everything just went black. It still powers on alright, light blinking like normal, but the screen is like dead now.
I have tried resetting in blind mode (randomly pressing F2, F9, Enter, F10, Enter), but obviously it didn't do anything.
I also have tried disassembling, taking out the CMOS battery and pressing the power button without battery or charger plugged in for 10 minutes and it seems to have not done anything as well.
Plugging in an HDMI screen turned out useless too. There's also a DVI port on the laptop, would using it be any different from HDMI? I don't have a cable so can't try right now.

I'm quite desperate now and have no idea what can I do to save it from the dark.
Any answer would be appreciated.

 

[Innocentius_C]

So I was able to bring the display to life by flashing a modded BIOS (found it on notebookreview). I guess flashing the original would work too, but anyway, it kinda works now and that's what was needed.

 

[Ceel Mogami]

So I was able to bring the display to life by flashing a modded BIOS (found it on notebookreview). I guess flashing the original would work too, but anyway, it kinda works now and that's what was needed.

Hi I have a similar problem with my 4820TG and I was wondering how you concretly managed to solve your problem. I found the modded BIOS downloads on notebookreview (http/forum.notebookreview.com/threads/acer-aspire-timelinex-4820tg-5820tg-modded-bios-insyde.568951/) but it isn't very clear to me how I should proceed with the actual BIOS flash. What is unclear to me is what I should put on the usb flash drive when let's say I download the modded BIOS v1.25. And also what I should rename ZQ1X64.fd at that point.... (the folder? the .exe file?). I have tried many different combinations but all have failed for now. I hope you can shed some light upon this darkness. Thanks. C.