Hi @adyopo
How did you reset the BIOS? Did you disconnect the RTC coin cell battery from the motherboard when you did this?
If not try the following procedure and check if it resolves the problem.
* Disconnect the charger from the laptop if connected.
* Remove the main battery from the laptop.
* Disassemble the laptop and disconnect the RTC coin cell battery from the motherboard. Here's the [https://thinkpads.com/support/hmm/hmm_pdf/t440p_hmm_en_sp40a25467_01.pdf|hardware maintenance manual] for the laptop that will help. Go to the bottom of p.65 to view the procedure. When the RTC battery has been removed, measure its voltage. If it is <2.5V DC, replace it. Search online for ''04W1642'' to find suppliers that suit you best.
* ''Press and hold the laptop's Power button for a full 30 seconds and then release it.''
* Reconnect the RTC battery, reassemble the laptop, reinsert the main battery, reconnect the charger and check if the laptop turns on OK.
If it does turn on there may be a message regarding the date and time being incorrect, this is normal as the BIOS has been reset. Once the D&T have been corrected the message won't appear the next time the laptop is started. Also if any user definable BIOS settings have been altered to suit whatever operating requirements that you have, they will have to be changed back as well.