[Blank Screen] LCD Problem or Another Hardware Failure?

Hi,

Try a full power refresh in case it is a corrupted BIOS and check if that resolves the problem.

Here’s the procedure:

a). Disconnect the charger from the laptop if connected.

b). Remove main battery from the laptop.

c). Disconnect and remove the RTC coin cell battery from the motherboard.

Here’s the hardware maintenance manual for the laptop. Go to p.81 to view the necessary pre-requisite steps and then the procedure to remove the RTC coin cell battery.

When the RTC battery is removed measure its voltage. If it is <2.6V DC replace it. The part number is 01HX685. If you search online using the part number only, you will find suppliers of the part.

d). Press and hold the laptop's Power button for 30 seconds then release

e.) Reconnect the RTC battery (or its replacement).

f). Reverse the above steps to re-assemble the laptop.

g.) When the laptop is completely re-assembled, connect the charger and try to turn on the laptop.

If it starts OK there may be a message about the date and time being incorrect. This is normal as the BIOS has been completely reset back to its default settings. Once the date and time have been adjusted the message won’t appear the next time that the laptop is started.

If you had previously changed any user defined settings in BIOS to suit whatever specific hardware configuration that you had for the laptop, then these will have to be set again.

Based on the symptoms you described, it sounds like your Lenovo ThinkPad T470 may have a hardware problem. The fact that the fan and keyboard backlight turn on but the LCD screen remains blank suggests that the problem may be with the LCD itself or with the cable that connects the LCD to the motherboard.

If you have access to another ThinkPad T470, you can try swapping the LCD screens to see if that fixes the problem. If it does, then you know that the problem is with the LCD screen. If it doesn't, then the problem is likely with the cable or with the motherboard.

If you don't have access to another ThinkPad T470, you can try contacting Lenovo support for help. They may be able to diagnose the problem over the phone or they may send you a replacement LCD screen or cable.

Here are some additional troubleshooting steps you can try:

1. Check the LCD cable. The LCD cable is the cable that connects the LCD screen to the motherboard. If the cable is loose or damaged, it can cause the LCD screen to go blank. To check the LCD cable, disconnect it from the motherboard and then reconnect it. If the LCD screen still doesn't work, then the cable may be damaged.
2. Reset the BIOS. The BIOS is the software that controls the basic functions of your computer. Sometimes, resetting the BIOS can fix problems with the LCD screen. To reset the BIOS, follow the instructions in your computer's manual.
3. Update the BIOS. Lenovo often releases BIOS updates that fix problems with the LCD screen. To update the BIOS, go to the Lenovo website and download the latest BIOS update for your computer.
4. Contact Lenovo support. If you have tried all of the above steps and you are still having problems, you may need to contact Lenovo support for help.

@hendra90934 if you have checked everything, like your HDD/SSD/RAM etc then the issue is either your processor or you somehow have a failed BIOS. You cannot repair the BIOS since you do not have access to writing to it. The only other way I know woff is by replacing the actual BIOS chip. You can purchase pre=programmed BIOS IC. Check places like this. REmember so, the BIOS is soldered to the motherboard. That means you will have to remove the board and then desolder the old BIOS and resolder a new BIOS. Soldering on a motherboard is not quite as easy as it sounds, so you will need to have decent tools and good skills.