Hi there, it is difficult to tell whether the Dell monitor or the USB-C cable is the culprit, you're recommended to make a test by unplugging the monitor and trying an alternative cable respectively. On top of that, there are some other solutions you can try :
- Detach all external devices from your Mac
- Reset the SMC
- Let your MacBook charge for a longer time
- Perform a power cycle on your computer
- Check the display brightness settings or try to use an external monitor
- Seek repair service
For more information, please visit this article from the iBoysoft website: MacBook Pro/Air Won't Turn On or Start? Make it Boot Now
Good luck~
Rivers Wong
Eudora Liu
Jenny Zeng
Connie Yang
