07-19-2016 04:35 AM
Hello All, my 5 years old Thinkpad t420 does not power on. the power button blinks and then does nothing. After reading about the same issue on forum, i found out that system board might need replacement.
Is it possible to fit any other system board in this laptop (i am looking for a cheaper option like:63Y1989 FRU instead of 04W02049 FRU which is installed in my system).
or would it be better to go for a new laptop?
PS: i had bought 2 years extended warratny and got its LCD, keyboard and hinges also replaced during the same time. I have plugged in quite a bit of money in it. but i am fearful of putting anymore money in this thing. It seriously lacks the relaibility for which i had purchased it.
07-19-2016 09:00 AM
Before spending money in a new mobo, have you tried this good 'ol trick?
You're also sure the AC adapter works fine?
07-19-2016 09:13 AM
Thanks for the reply. Based on the forum reads, I have tried the combinations that you have suggested: removed battery and tried to purge the residual charge by pressing the power button.
Adapter is working fine as the system is powering up without battery.
Not sure what to do next.
07-19-2016 11:29 PM
My next step would be to remove the harddrive, the wlan card (and wwan if available) and RAM (one module is located on the bottom of the laptop, the other under the keyboard). Then turn the T420 on without battery, you should hear a series of beeps, if you don't hear any beeps then a motherboard failure is more likely.
You can download the hardware maintenance manual from Lenovo from here: click me! and check the instructions on chapter 8 - 1040 to 1090
If you're sure that your T420 has no supervisor password for the BIOS, you could also remove the BIOS battery, leave it out for 15 minutes and put everything together again.