Hi @no_username
If it still doesn't work try a full power refresh and check.
What can sometimes happen is that the BIOS can become corrupted preventing a normal start. Draining all the power from the motherboard causes the BIOS to default back to its factory default state.
* Disconnect the charger if connected.
* Remove the main battery from the laptop.
* Disassemble the laptop and remove the motherboard from the laptop. Then remove the RTC (Real Time Clock) coin cell battery on the ''underside'' of the motherboard. Here's a teardown [https://www.youtube.com/watch?v=AuqV2_ISg9I|video] that may help. The RTC coin cell battery can be seen at 10:13 minutes into the video. When you have removed the RTC battery, measure its voltage. If it is <2.5V DC replace it. The battery model number is on the battery itself. It might be a CR2032 but double check.
* Reinsert the RTC battery (usually +ve is on top, printed on battery)
* Reassemble the laptop, reinsert the main battery, connect the charger and check if it turns on.
If it turns on OK, there may be a message about the date and time being incorrect. This is normal because the BIOS as been reset. Once you correct the date and time, the message won't appear the next time the laptop is started. Also any user defined BIOS settings that ''you have changed,'' to suit whatever operating requirements you have, will need to be changed back to what you changed them to, from their default state.