Hi @johndoe23811
When the error occurs, if you restart the laptop and get in BIOS on startup, does the SSD information i.e. make and model number, appear in BIOS > System Information > Device information?
If it does this may indicate that the boot partition in the SSD is corrupted.
Perhaps check if the RTC coin cell battery voltage is OK.
Here's the owner manual for the laptop. Go to p.19 to view the procedure to remove the coin cell battery from the motherboard.
Regarding the main battery, you don't have to remove it, just disconnect the battery cable from the motherboard.
When the coin cell battery is out, if it is <2.4V DC or if the battery is >4-5 years old, replace it. Search online for C8KT2 to find suppliers that suit you best.
Before reconnecting the coin cell battery (either original or replacement) press and hold the laptop's Power button operated for a full 30 seconds and then release it.
Then reinsert and connect the coin cell battery, reconnect the main battery, close the laptop, connect the charger and check if it turns on and boots OK.
If it does there may be a message stating that the date and time are incorrect. This is normal as the BIOS has been reset back to factory default by the above. Once the date and time have been corrected, the message won't appear the next time the laptop is turned on.
Also any user definable BIOS settings that were changed by you to suit whatever system requirements you had, will need to be changed back again also.