Don’t give it a test if you intend to repair it. Sending power to the motherboard will fry it if there are problems. It’s not just liquid but the acid. If you have data backed up and have no intent to pay for repair, you can try.
Otherwise, either pull the hard drive so you can migrate data to another computer or find a repair shop.
On a computer in HK, no idea on compatibility with U.S. I do think I fried a laptop by plugging it in to local power in HK with just an adapter. You have to look at the brick on the power supply and see what the input range is. If HK power and US power are both within the range of the power supply, it will convert to the proper voltage for the computer. I defer to people for more knowledgeable than me about electricity.