your CMOS battery may be dead or outdated logic board firmware. Try downloading the most current firmware for your logic board from Dell’s website- since you’re running Ubuntu you can’t use their Dell Command Update program to keep these updated.

Disassembling the laptop with it in Hibernate mode and not fully powered off may have damaged the logic board. These HP laptops are also known to sit for well over a minute building the BIOS when the battery is removed/replaced. Hold down your power button for 15-30 seconds and then power it back on.

Disinfecting wipes may also be conductive as they use water, electrolytes and other cleaning chemicals.

You need to remove the battery to remove power from the laptop. You should always isolate the power before working on any electronics.

It’s usually a cost saving measure to use a softer alloy on the screws. Try using a screwdriver with less of a point on the very tip, more of a flatter tip will give you more surface area contact and will help save you from stripping screws.