System board <00a> error message

[Olam7]

My laptop also does not recognize my power cord. 
However, when I turn it off and leave it plugged in, the battery is full, but when I turn it back on it stops charging. 
But when the laptop is on and plugged in, it looks as if it is not plugged in and functions of of the battery. 
Both things accured at the same time (day before yesterday) AND my laptop is super slow all of the sudden.
Streaming movies is almost impossible, it's so choppy. Regular websites take forever to load and freeze randomly. 
HOW can this be fixed? I'm not a techy, so please tell me things I can actually do (besides turn it on and off/rebooting).
I ordered a new power cord and battery, they will arrive tomorrow. 
However that doesn't fix that "System board is missing or invalid..." message at start up. 
HELP!!

[TEJ1602]

@Olam7, Welcome to HP Support Community!

May I have the exact model name of the product? Refer to this document for steps to find the product details. Do not share any of your personal information such as serial, phone number, email ID, etc.

Keep me posted.