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Asus G74SX Keyboard Backlight Fix

C4RN1
Level 9
I'm posting this to help the community.

I fixed the backlight on a G74SX I have had since March (will post the story tomorrow). Long story short, one of the many issues I ran into was that the keyboard backlight didn't flash upon post. I researched this for about 3 or 4 hours and finally stumbled upon a post back in 2013 that had a bad link because the webpage had been deleted. I used the wayback machine to view the post and edited the link to find that the rom file was still available on a microsoft onedrive account.

I am recreating the original post here with my links.

Keep in mind I didn't create this fix but I have tested this method and can confirm that it works.

Here is the original page recreated

Posted on July 4, 2013



Whilst looking at a number of different Asus G74SX gaming laptops, a common issue became very apparent. I noticed that the backlit keyboard wasn’t illuminating / working at all. I stripped the machine down, and reconnected the backlight cable, after cleaning the contacts with IPA. This had no effect. I also tested a known working keyboard, which produced the same result.

On a working G74SX during POST, the keyboard backlight flashes on then off. This wasn’t happening on this particular machine. The FN + F3/F4 keys didn’t function also under Windows.

As the keyboard wasn’t flashing during POST, I came across two possible causes:

1. The BIOS isn’t functioning correctly, and not producing any output to the keyboard backlight
2. The motherboard has become defective

I started at point 1, and immediately began to flash the BIOS. The BIOS was at the latest version, 203, so flashing under Windows wasn’t an option, as this would produce an error.

I used the AMI AFUDOS tool from DOS with option /x (to surpass compatibility checking) to flash the BIOS, using command: AFUDOS G74SX.ROM /x

The flash was successful, however the backlit keyboard was still not functioning.

I decided to save the BIOS of a known working G74SX. This was done using the /o option.

I then proceeded to use the Asus EasyFlash that is intregrated into the BIOS Setup, to flash with the newly created ROM.



After the flash was complete, I restarted the laptop. The keyboard backlight was now fully functional, and the FN + F3/F4 keys were now functioning fine.



I have uploaded the ROM file here.


Before you download the file go here.

https://rog.asus.com/forum/showthread.php?11080-BrodyBoy-simple-but-effective-pdf-guide-on-quot-Upda...

After reading the tutorial on how to flash your bios using easyflash you can proceed to download the file below.

https://www.dropbox.com/s/24qrjtz13i64o0y/G74SX_Fix_KB_Lights.zip?dl=0
22,593 Views
14 REPLIES 14

Salamakhin
Level 7
It's working)) thank you man.

can't download the pdf for some reason,
it just bring me on a log in page loop 😞
Asus G74SX-A1

jamcghie
Level 7
It worked!!! After like 3 years of no backlight! I was afraid to update bios because I have had 2 computers fail before. I gave it a shot, and I am happy! Thanks for the find/fix!


Ok, wow. Final edit. You need to right click link and save linked content. So used to direct links to downloads. Got it! :
D

muphybird
Level 7
C4RN1 wrote:
I'm posting this to help the community.

I fixed the backlight on a G74SX I have had since March (will post the story tomorrow). Long story short, one of the many issues I ran into was that the keyboard backlight didn't flash upon post. I researched this for about 3 or 4 hours and finally stumbled upon a post back in 2013 that had a bad link because the webpage had been deleted. I used the wayback machine to view the post and edited the link to find that the rom file was still available on a microsoft onedrive account.

I am recreating the original post here with my links.

Keep in mind I didn't create this fix but I have tested this method and can confirm that it works.

Here is the original page recreated



Before you download the file go here.

https://rog.asus.com/forum/showthread.php?11080-BrodyBoy-simple-but-effective-pdf-guide-on-quot-Upda...

After reading the tutorial on how to flash your bios using easyflash you can proceed to download the file below.

https://www.dropbox.com/s/24qrjtz13i64o0y/G74SX_Fix_KB_Lights.zip?dl=0


The link you have provided at www.dropbox.com is for what? Is it the latest bios 2.03 for G74sx, or is it something else? If it's bios 2.03, would it not be better to get it from the Asus website?

C4RN1
Level 9

C4RN1 wrote:
The dropbox.com link is for the modified bios file to fix your keyboard backlight. I thought this was all explained in the first post?


No where in that post did I see the term modified bios file. Regardless, I fail to understand how anyone would be foolish enough to use a modified bios file from an unknown site, let alone a dropbox and risk bricking their laptop. I also fail to understand why Asus seems to be providing very poor support to their G74SX product line. I'm sure they monitor sites like this to see what customers have to say about their products.

C4RN1
Level 9
Let me help you understand so you're not confused.

Back in early 2010 we found that sometimes the keyboard backlight on the G73 would become inoperable due to a bios flash or driver update. After trying to reinstall the correct ATK drivers we noticed that the keyboard backlight didn't even flash upon boot. Thinking this was a hardware failure the keyboards were swapped out for known working ones but the problem remained.

Gary (probably an over-achieving tech from Asus) came up with a solution. Eventually he would rewrite the part of the bios that controls the keyboard backlight to restore functionality.

http://forum.notebookreview.com/threads/keyboard-light-fix-gary-key.513264/

Keep in mind that more than likely Asus was replacing motherboards before he found this solution. Also keep in mind that this has never been uploaded/available on Asus servers.

As for the G74, there has never been any support from ASUS for more complex issues. You should look around this site and see all the horror stories of RMA and just pain negligence from ASUS. The community supports these systems, not ASUS.

In late 2012 one of the truly breakthrough moments in our community was when we learned how to extract, modify, and flash a bricked board using an SPI Programmer.

http://forum.notebookreview.com/threads/g74sx-in-circuit-reprogram-of-bios-spi.656498/

If you read through the first few pages you will understand how Sir Robin extracted his corrupt bios to modify it and get his machine back up and running.

This technique is more/less how the G74 kb backlight fix came about. A over-achieving computer tech decided to dump a working bios from a g74sx to fix an issue that ASUS couldn't.

Hope you understand now!