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View Full Version : G75VX Weird LCD not working problem, haven't found anything like it.



StrangerHacks
05-12-2017, 03:12 AM
I have a G75VX that's really been though it's work over the years, broken LCD, replaced LCD, bad BIOS flash, reprogrammed BIOS, laptop works over HDMI but internal display doesn't work (doesn't even come up in display settings), figured maybe it's a bad motherboard so I replaced that, LCD still doesn't come up even on the new motherboard (BIOS 204), tried to update new motherboard BIOS to 206 (hangs on verify and won't flash the new BIOS), I can't use Easy Flash BIOS because I can't access the BIOS over HDMI and the internal display doesn't even come up as being on, I've had this laptop apart and tested as far as I can with everything and it all should work just fine.

I figured the new motherboard might be faulty so I actually swapped the BIOS chips from one motherboard to the other, I'm now back on the original motherboard with a new BIOS chip, and the original BIOS chip on the new motherboard just to see if maybe it was a board/bios issue, same result with both boards, original chip is BIOS 206, new one is 204, new one won't update to 206, both motherboard don't show the display at all, only one display comes up saying HDMI is display one, but BIOS won't show up over HDMI.

I'm really at a loss here and I don't know what to do with this laptop, I've dumped so much money into this thing chasing issues I could have bought a new laptop by now.

Any suggestions? Does anyone know if the BIOS can be accessed over VGA? I don't have a cable around but I can probably source one locally if someone can confirm that will work to see if I can access Easy Flash BIOS over it to update this new BIOS chip to 206 and see if that will make it see the internal display.

Secondly, how do I test a display to see if it works? It worked 100% before the bad BIOS flash and since then I have been having display issues, can a bad BIOS flash fry a display? That's the only thing I'm left thinking happened which means I need to replace the display again but need to know if these are actual issues before I dump more money into this thing.

Any help is greatly appreciated

TeflonJon
05-31-2017, 05:44 AM
I was/am having this same issue with the internal screen not being detected after a BIOS flash. I'm not sure about why your BIOS wouldn't come up over HDMI, what buttons are you pressing to bring it up? If your BIOS is at default settings then fastboot and secureboot are probably enabled. Holding down F2 while I press the power button usually works to get me into BIOS, but if that doesn't work try holding down shift while you press restart from inside windows then it'll reboot into UEFI mode and you should be able to get into your BIOS from there. After that, If you can get into BIOS settings, disable fastboot, disable secure boot and disable the "launch CSM" setting, save changes and exit and I bet your internal screen will turn on by the time the login screen comes up.

jakwolf67
08-06-2018, 02:51 PM
Mine also has the same issue after writing an overclocked custom bios to the system. At first the built-in display was just not the default for post nor windows but still detected so I just used the windows display settings to use the built-in as the primary (strangely still needed to be done, even without a 2nd monitor actually connected). This was sort of fixed, but I couldn't use the built-in for post and the bios settings without an external monitor (more annoying than it sounds actually). Thus, in desperation to perfect this, I reverted back to the official .206 bios, but then the built-in display didn't detect AT ALL. Wow, in desperation I bought an eprom programmer with chip clips and aquired a copy of the official 8MB .206 FULL bios dump to reflash... this flashed successfully yet the monitor STILL doesn't detect AT ALL. I've attempted to flash just the 670MX vbios alone with nvflash but this specific Asus ROG 670MX is apparently not supported by nvflash according to it's error (hardware id not supported) and everyone says the vbios is in the .206 main bios anyways which flashes both the bios and vbios at the same time (still not confident about that).

At this point I think maybe it's the lcd cable or graphics card. I'm getting a replacement cable as I feel maybe I damaged it by taking apart the laptop to reseat the cable. Perhaps I crimped it or something, I don't see any signs of damage though but it is very fragile and one wrong pull, bend, twist, or crimp by not installing it very careful and proper within the laptop bezels could reasonably damage it under the pressure of closing the lid while it is exposed and crimped by bezel and hinges. MAYBE that is the case, but it could honestly be some kind of EDID corruption of the LCD itself or graphics card vbios corruption still.

Damn this has been a very long term project and I've put it off for awhile several times just about ready to sell it for parts AS IS on ebay for maybe half the current rate of a working unit (which is still half of what I originally paid which is expected by now). Bah, this has been the ultimate mystery in my pretty tech savy experience. Along with these steps, I've also tried maybe 30 other steps so far without success. Power cycling, removing the CMOS battery, shorting the two CMOS reset Pins near the bottom memory slots whilst booting, etc.