Jump to content
EwinRacing Flash Series Gaming Chairs
Arise

Asus G750 CMOS reset or BIOS reset

Recommended Posts

I'm trying to clear CMOS for my Asus G750 laptop, but so far no luck.

Activated a couple of hidden settings in BIOS and after saving and rebooting I get a black screen, laptop not posting.

So I tried to recover it by:

- remove big battery

- remove power cord

- removed the small circular 3.3V battery for RTC

- shorted the RTC battery pins with a small coin

- kept power button pressed for 1 minute

So far nothing...

I was only able to recover by rewriting the BIOS chip with a SPI programmer.

This is kinda stupid, and I feel annoyed, how do I reset the damn BIOS?

After recovering went to bios, and set a couple of settings like Hypertreading from enabled to disabled and short power boost from 24 to 28.

Tried again to reset BIOS with the above steps and nothing... :(

The settings are kinda persistent.

I really need a solution to this, can't disassemble half of my laptop every time I mess up with some unlocked BIOS settings.

Share this post


Link to post
Share on other sites

You gotta find the pinout of the CMOS chip for your mobo then short the DATA pin to a ground when you boot.

Share this post


Link to post
Share on other sites

Hello,

On my G75VW, there are 2 jumpers JRST2001 and JRST2002 near RAM. Those are for CMOS+Bios reset. I don't know if you have similar feature with your laptop.

Share this post


Link to post
Share on other sites

ImageUploadedByTapatalk1457386894.691150

I can confirm those two jumpers are next to the user replaceable memory sockets on Asus G750.

Sent from my iPhone using Tapatalk

Share this post


Link to post
Share on other sites

I did a lot of combinations (without battery, with and without power cable with and without CMOS battery inside of laptop).

 

It seems that if the CMOS battery is installed, with no other power, then shorting the JRST2002 will make the laptop not POST-ing. If I short the JRST001 it will unbrick it.

 

If I remove the CMOS battery, then if there is no power cable or battery it seems I lose the date/time. But all other options are preserved in BIOS. Shorting JRST2002 will do nothing it seems without that 3.3V CMOS battery.

Shorting the JRST2001 will make the laptop reboot if the power cable is on, but no BIOS changes will be reset back to default values.

 

So... right now I am stuck, don't know if those jumpers are working as they are supposed on Asus G750.

Share this post


Link to post
Share on other sites

After some more testing I can say that shorting JRST2002 and then JRST2001 will reset the system date/time back to 2009. But the settings in BIOS will be preserved, those are not erased.

Share this post


Link to post
Share on other sites

The same is for the G46VW. I tried all combinations and the JRST2002/2001 and had the same results as you. I ended up ordering a programmed bios chip and then had to desolder the old chip and solder the new chip on. All worked again after that. 

Share this post


Link to post
Share on other sites
On 3/8/2016 at 4:48 PM, Arise said:

I did a lot of combinations (without battery, with and without power cable with and without CMOS battery inside of laptop).

 

It seems that if the CMOS battery is installed, with no other power, then shorting the JRST2002 will make the laptop not POST-ing. If I short the JRST001 it will unbrick it.

 

If I remove the CMOS battery, then if there is no power cable or battery it seems I lose the date/time. But all other options are preserved in BIOS. Shorting JRST2002 will do nothing it seems without that 3.3V CMOS battery.

Shorting the JRST2001 will make the laptop reboot if the power cable is on, but no BIOS changes will be reset back to default values.

 

So... right now I am stuck, don't know if those jumpers are working as they are supposed on Asus G750.

 

On 3/8/2016 at 6:21 PM, Arise said:

After some more testing I can say that shorting JRST2002 and then JRST2001 will reset the system date/time back to 2009. But the settings in BIOS will be preserved, those are not erased.

 

hi, im sorry for bumping this old thread, but i got bios problem too, my laptop is asus n46vz, the thing is i changed some settings in my bios, after save change & restart, my screen is completely black but keyboard light , notification light all lights up. so i wanted to ask, does ur asus fixed after u do this ? 

Edited by Blitzhartwright

Share this post


Link to post
Share on other sites

Try the Ctrl+Home pressed and while keeping them pressed press power button. It should hopefully attempt to boot from USB stick and reflash the bios. The bios must be on a simple USB stick formatted as FAT32. The filename for recovery can be obtained with andytools.

If this will work you will see the usb led for activity flashing differently than usual. So if usb is flashing then is only a mater of matching the filename/firmware.

Sent from my iPhone using Tapatalk

The other option would be the recovery using a SPI chip programmer.

Sent from my iPhone using Tapatalk

Share this post


Link to post
Share on other sites
On 5/29/2016 at 4:16 PM, Arise said:

Try the Ctrl+Home pressed and while keeping them pressed press power button. It should hopefully attempt to boot from USB stick and reflash the bios. The bios must be on a simple USB stick formatted as FAT32. The filename for recovery can be obtained with andytools.

If this will work you will see the usb led for activity flashing differently than usual. So if usb is flashing then is only a mater of matching the filename/firmware.

Sent from my iPhone using Tapatalk

The other option would be the recovery using a SPI chip programmer.

Sent from my iPhone using Tapatalk

hi, i already did the ctrl+home, the usb did flash differently, but after that nothing happen, the screen still blank.

i dont know if the BIOS filename in the usb is correct or not, but i already tried a bunch of names, but nothing.

u can see all the names i've tried below :

Capture.PNG

 

and, does shorting JRST2001 fixed ur asus ?? because i see from this thread > https://rog.asus.com/forum/showthread.php?66837-Hard-CMOS-Reset-Solution-For-dead-G75VW

and his asus come back to life.

 

oh, and what is this "andytools" u're talking about ?? never heard of it.

Edited by Blitzhartwright

Share this post


Link to post
Share on other sites

You can find PhoenixTool on digital life forum or on the net.

When you open the recovery BIOS file in PhoenixTool it will show a popup with the recovery file name that must be used.

 

Shorting JRST2001 for me actually bricks the laptop, to unbrick it I also have to short the JRST2002 pin. Cant say exactly what is doing, didnt investigated much as I discovered it won't help me with the NVRAM persistence.

Share this post


Link to post
Share on other sites
15 hours ago, Arise said:

You can find PhoenixTool on digital life forum or on the net.

When you open the recovery BIOS file in PhoenixTool it will show a popup with the recovery file name that must be used.

 

Shorting JRST2001 for me actually bricks the laptop, to unbrick it I also have to short the JRST2002 pin. Cant say exactly what is doing, didnt investigated much as I discovered it won't help me with the NVRAM persistence.

okay, after using PhoenixTool

 

Captur1e.PNG

Share this post


Link to post
Share on other sites

Either of them should work, add one to a USB stick and try with Ctrl+Home then Power button.

Filesystem of the rescue drive should be FAT32.

If not working, then try with another stick. :) Or a sdcard in a cardreader. 

Eventually it should work...

Share this post


Link to post
Share on other sites
10 minutes ago, Arise said:

Either of them should work, add one to a USB stick and try with Ctrl+Home then Power button.

Filesystem of the rescue drive should be FAT32.

If not working, then try with another stick. :) Or a sdcard in a cardreader

Eventually it should work...

hmm, but in the list that i showed u earlier, i got one of them right :

Capture_2.PNG

 

or, because the PhoenixTool shows 2 of them does that mean, in my usb i should copy the bios twice and rename one of them to "N46VZ.bin" and the other one to "N46VZ.409" ?

Edited by Blitzhartwright

Share this post


Link to post
Share on other sites

You only need one file, but assuming your "desperate" situation, I will assume you will try both names anyway, whatever it works. :)

Try maybe with a different USB stick like mentioned above.

Share this post


Link to post
Share on other sites
20 hours ago, Arise said:

Shorting JRST2001 for me actually bricks the laptop, to unbrick it I also have to short the JRST2002 pin. Cant say exactly what is doing, didnt investigated much as I discovered it won't help me with the NVRAM persistence.

 

wanted to ask bout this, u said shorting jrst2001 will brick the laptop, and to unbrick it u need to short the jrst2002 too. my question is, when u unbrick it, did u get the "asus logo" / POST-ing ? 

 

also i get this image from french forum, and JRST2001 is indeed for clearing CMOS.

img2.uplood.fr_free_kkar_149.jpg

 

Edited by Blitzhartwright

Share this post


Link to post
Share on other sites

When I shorted the first pins (my laptop was just fine before that) it made it not booting.

When I shorted the other pins I was able to boot.

 

From my testing those jumpers will clear the CMOS data (whatever that means) and the time.

But it will not clear NVRAM settings (stuff you mess up while in BIOS menus) so it will not help with making your laptop bootable.

 

I consider bricked a laptop that displays nothing on screen. Keyboard could light up or... no.

Share this post


Link to post
Share on other sites
On 6/1/2016 at 7:11 PM, Arise said:

When I shorted the first pins (my laptop was just fine before that) it made it not booting.

When I shorted the other pins I was able to boot.

 

From my testing those jumpers will clear the CMOS data (whatever that means) and the time.

But it will not clear NVRAM settings (stuff you mess up while in BIOS menus) so it will not help with making your laptop bootable.

 

I consider bricked a laptop that displays nothing on screen. Keyboard could light up or... no.

hi arise.

wanted to ask bout nvram persistence u mentioned.

so the settings ive made in bios wont get resetted because of nvram persistence right ?

can i know how you fix ur laptop then ? what did u do ? 

until today my laptop not fixed yet its so damn frustrating, idk what to do anymore...

 

Share this post


Link to post
Share on other sites

Hi all friends,
Thank you for contributing in this usefull forum.
I unlocked my asus k43tk headen bios settings using a well-stablished modded bios, and it performed perfectly for some days. But then I decided to disable the weak integrated apu graphics HD6520G to use the more powerfull discrete HD7670m as the primary (and only) graphics card.
I think I carelessly changed the settings in the northbridge menu, and after saving and restarting I got a black screen. The fan and LEDs are working, and HD7670m was fully functional before these changes.
I removed the CMOS battery for 3 days to reset it but no success.
I downloaded my laptop board schematic, it has two separate spi flash memories for "system bios" and "EC" firmware (Embedded Controller); after I disassembled my laptop, I noticed that only the EC flash has been installed on the board, and the system bios flash footprint on the PCB (connected to Hudson-m3) is empty. Hence both system bios and EC firmware should be on the same flash. But are the bios configs also stored in the same BIOS flash memory?
I have also tried to recover the bios by copying original bios file on a flash drive and renaming it several times as the SUPER, AMIBOOT, K43TK, and BIOS, all with .BIN and .ROM formats, and holding ctrl+home while turning it on; but no success.

Dear RypeDub, shorting data pin (I think you mean MISO pin of SPI flash) will not damage the chip? It is not an open-drain output. And furthermore, when booting, the whole EC firmware and system bios will be read as zero.
Any help to reset the BIOS configurations to the default settings is appriciated.

Edited by K43tk

Share this post


Link to post
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.


×
×
  • Create New...

Important Information

By using this site, you agree to our Terms of Use. We have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue.