Acer Nitro 5 won't power on. blue light comes on for a few seconds

If the battery is still good and you have tried to boot with a different adapter, I recommend the Power Drain, RAM check and CMOS reset, if that also does not help bring the laptop to Acer Services in your country for checking, include the power adapter.
Open the back of the laptop and disconnect the battery cable from the motherboard. Locate the CMOS module (with 2 twisted wires Red and Black under the battery) and remove the coin battery. Shorten the +/- contacts inside the CMOS capsule for 2 seconds with a bended paperclip and put the coin battery back with the + sign facing up, close the CMOS capsule. Unseat the DDR4 modules and secure again firmly in the 2 slots. Next, press the Power Button on the keyboard for 10-15 seconds after that reconnect the battery cable to the motherboard. Close the laptop, plug-in the adapter and try to boot.