Use a USB multimeter like https://smile.amazon.com/dp/B07JYVPLLJ/r.... If you need something quicker, you can take the insulation off a USB cable, cut the red wire, switch your meter to amps, and hold the probes on the two sides of the red wire. If you see 0.5 amps or higher on the meter, the phone is charging.
Get a USB C to HDMI cable and plug in in. If it does not show up, you probably have a broken battery or motherboard. If it does you probably have a broken display.
Use a USB multimeter like https://smile.amazon.com/dp/B07JYVPLLJ/r.... If you need something quicker, you can take the insulation off a USB cable, cut the red wire, switch your meter to amps, and hold the probes on the two sides of the red wire. If you see 0.5 amps or higher on the meter, the phone is charging.
Andrew S さんによる