Although the Sleep and Hibernate options are configurable in the Settings app, a computer that cannot boot up from Shutdown cannot boot up at all. I’m not sure if you are saying that your computer is functioning poorly, or that it’s completely “dead” and won’t turn on. Please help me understand - what tasks are you trying to accomplish with your computer, and what exactly is the computer doing that is blocking you from finishing your work?
Take a look at the metal prongs on the plug of the electrical cord. Are they straight and untarnished? A charging cord with damaged prongs may need replacing. Check the cord/power supply interface. Is the cord’s connection to the power supply firm and stable? If all this checks out, then getting a new cord or power supply may fix the issue. I would try a new charging cord first since it would be less expensive.
It seems like you’re saying that the computer only has one working RAM slot because the other slot failed. It is still functional, however. And you are trying to reinstall the Macbook Pro OS, but it won’t install because of a firmware issue. Is this correct?
Opening a computer case can void its warranty. Please call Apple customer support at 1-800-275-2273 for more details. Now that the case has already been opened, have you tried replacing the battery? There is a tutorial at the following link: MacBook Pro 16" 2019 Battery Replacement
Your files should be safe since your computer’s hard drive doesn’t need a constant power source to maintain them. Everything should be up and running again once the battery is replaced and the technician runs a diagnostic on your system.
A good way to check the health of your Chromebook battery is to use the Crosh utility. To open up Crosh, press ctrl + alt + t on your keyboard. When Crosh opens, type battery_test at the crosh> prompt. This will start the battery health test. Since your battery is new, the health grade should be almost perfect. If it isn’t, then the battery will need to be replaced soon, if not refunded (if it is in fact refundable). The power jack of the Acer Chromebook CB3-111-C8UB is soldered onto the motherboard, and is therefore difficult to replace. You could buy a whole new motherboard, but the whole process (motherboard, tools, shipping costs) may end up costing more than the laptop itself.