laptop turns off when charger is unplugged
i have an Asus vivobook X542UN
i took it to a repair shop to upgrade my ssd (so this happened after it was opened) and now the laptol only runs on the charger and turns off immediately if i unplug it
the battery is almost new and it ran like a charme before it was opened
the repair shop wouldn't take responsibility for what happened so im trying to fix this myself now, what might be the problem and how do i fix it ?