When you said "...tried restarting it by taking out the batteries.", did you mean the coin cell RTC (aka cmos) battery as well?
If not try a full power refresh and check if that resolves the problem.
a). Disconnect the charger from the laptop if connected.
b). Remove the main battery from the laptop.
c). Disconnect the RTC battery from the motherboard.
Here’s the hardware maintenance manual for the laptop. Go to p.68 amd p.74 to view the procedure to remove main battery and the RTC battery.
When the RTC battery is removed measure its voltage. If it is <2.6V DC replace it. The part number is 04W1642. 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 a full 30 seconds and then release it.
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.