Chosen Solution
I have a Samsung 370R laptop that doesn’t want to charge or stay on mains power. I’ve metered the charger at 19v, so all good. No broken connections in the cable that I can find. I’ve replaced the charging port, to be in the safe side. No joy. It only says charging for a split second when plugged in, then discharges. When it does boot up I adjust the brightness, but no matter what I do it stays the same brightness. Boots into windows and Linux fine. I’m assuming the motherboard is fubar?!
If the device won’t charge, the battery may be the source of the problem. I would replace it before swapping out the motherboard.