Question HP Pavilion laptop power on after few months

[khchuang]

I have a hp Pavilion laptop.
After changing to a new battery, it worked for few months before it suddenly not able to power on. There was no charging light turning on at the charging port when I plugged in AC.
I tried many methods suggested at web but none of them work. The battery was charged since I can power up device with its USB ports.
Then I left the laptop on the shelf and forgot about it since I have another laptop to use.
Few months later, I plugged in AC and surprisingly the light at charging port turns on, and the laptop can power up !!

I don't know why and how, but I found the thread below having similar observation.
I afraid my laptop will suddenly down and won't be able to power on again.
Does anyone have the same experience and know why it can power up suddenly after leaving untouched for months ?

Multiple HP Laptops not turning on after charging port replacements
https://forums.tomsguide.com/thread...arging-port-replacements.428554/#post-1831724

 

[hang-the-9]

Intermittent issues like this can be due to small issues on the motherboard that settle and make proper contacts. It may have needed to have the motherboard reset also through not having power for a bit.

 

[khchuang]

I only changed the battery and didn't touch at other components.
I believe the only way to reset the motherboard is to remove the battery.

One thing weird about it is the USB port can power up USB device when I have AC plug in (with battery removed), That means the AC charging port is working, it just doesn't charge the battery, and power up the laptop.