04-20-2016, 04:24 AM
Laptop Model : Toshiba M840 B500 Part No PSKFJV
Core i7 3632QM, AMD Radeon HD 7670m 2 GB graphics card.
Motherboard A000176450 DABY3CMB8E0 REV:E
I was trying to enable switchable graphics from bios using EFI shell (Assuming that the laptop had that feature and it was disabled by the manufacturer.)
So I changed several variables in the bios. But they didnt enabled the intel HD graphics.
So At last I tried to change my primary display to (SG) swtichable graphics (thinking that if anything bad occurs i could reverse using Load Default Settings in my BIOS)
So i changed the variable 0x192 to 3.
After that the system didn't start. ( so i couldn't change to Default settings in bios )
The led was blinking.Caps Lock was working. WiFi led was working.
Then i had a lot of research about resetting bios. And I did a lot to things to unbrick it.
1. Removed the CMOS battery for 1 Day
2. Connected to external monitor using VGA and HDMI cable while booting and tried several key combinations like fn+B while booting.
3. Connected to external monitor after disconnecting the LCD display of laptop and key combination.
4. Tried to short the jumper G2001 (I dunno whether its the real jumper or not. I assumed it after watching some youtube videos and some articles after using google translate-they were not in English) . (pic given as attachment)
5. Used crisis mode. By booting a USB having my bios file BIOS.fd in FAT format and by pressing Fn+Esc while turning on. But this also didn't work (Laptop didn't read the USB). But one thing occurred. After this my laptop's power LED started blinking. Now if i turn on my lap the led will blink for some time then only it will become steady and the fan starts. Now the Caps lock or WiFi indicator is not working.
6. I took my lap to Toshiba service center and they told me that i have to replace my motherboard which will cost me around 200$. But i wasn't ready to replace it since i knew that all my other components was working fine before.
Now I am thinking to replace the bios chip in my MB
So I have some doubts regarding that. Hoping that some experienced users will help me
My doubts are.
1. Is there any other things i should try before changing the BIOS chip?
2. Since I changed a variable using UEFI shell. will it be saved in CMOS? So even if I change the BIOS chip. Only data in bios chip will be replaced.
CMOS wont be changed. Whether the problem will continue or not?
3. Do I need to buy another bios chip and program my bios into it and Resolder it to my MB. Or can I reprogram the same chip without taking it out of my MB?
4. My Lap have dual BIOS chip Winbond 25Q32 (4 mb) and Winbond 25Q16 (2 mb). My bios.fd file is 6 mb. Which chip I have to reprogram and how to?
5. For Reprogramming of my BIOS can I use the BIOS update file provided by Toshiba's Website, or do i need to get the original file?
Thanks in advance
Core i7 3632QM, AMD Radeon HD 7670m 2 GB graphics card.
Motherboard A000176450 DABY3CMB8E0 REV:E
I was trying to enable switchable graphics from bios using EFI shell (Assuming that the laptop had that feature and it was disabled by the manufacturer.)
So I changed several variables in the bios. But they didnt enabled the intel HD graphics.
So At last I tried to change my primary display to (SG) swtichable graphics (thinking that if anything bad occurs i could reverse using Load Default Settings in my BIOS)
So i changed the variable 0x192 to 3.
After that the system didn't start. ( so i couldn't change to Default settings in bios )
The led was blinking.Caps Lock was working. WiFi led was working.
Then i had a lot of research about resetting bios. And I did a lot to things to unbrick it.
1. Removed the CMOS battery for 1 Day
2. Connected to external monitor using VGA and HDMI cable while booting and tried several key combinations like fn+B while booting.
3. Connected to external monitor after disconnecting the LCD display of laptop and key combination.
4. Tried to short the jumper G2001 (I dunno whether its the real jumper or not. I assumed it after watching some youtube videos and some articles after using google translate-they were not in English) . (pic given as attachment)
5. Used crisis mode. By booting a USB having my bios file BIOS.fd in FAT format and by pressing Fn+Esc while turning on. But this also didn't work (Laptop didn't read the USB). But one thing occurred. After this my laptop's power LED started blinking. Now if i turn on my lap the led will blink for some time then only it will become steady and the fan starts. Now the Caps lock or WiFi indicator is not working.
6. I took my lap to Toshiba service center and they told me that i have to replace my motherboard which will cost me around 200$. But i wasn't ready to replace it since i knew that all my other components was working fine before.
Now I am thinking to replace the bios chip in my MB
So I have some doubts regarding that. Hoping that some experienced users will help me
My doubts are.
1. Is there any other things i should try before changing the BIOS chip?
2. Since I changed a variable using UEFI shell. will it be saved in CMOS? So even if I change the BIOS chip. Only data in bios chip will be replaced.
CMOS wont be changed. Whether the problem will continue or not?
3. Do I need to buy another bios chip and program my bios into it and Resolder it to my MB. Or can I reprogram the same chip without taking it out of my MB?
4. My Lap have dual BIOS chip Winbond 25Q32 (4 mb) and Winbond 25Q16 (2 mb). My bios.fd file is 6 mb. Which chip I have to reprogram and how to?
5. For Reprogramming of my BIOS can I use the BIOS update file provided by Toshiba's Website, or do i need to get the original file?
Thanks in advance