My Inspiron 5000 series won’t shut down/restart when I attempt too. I have tried almost everything I can find on YouTube and it still won’t shut down.
remove all external devices except keyboard mouse , connect monitor , make sure that powersupply unit is cables are connected to motherboard .
make sure front panel power usb cable properly connected to motherboard .
Blow with compressed air to motherboard
check with another powersupply unit
remove CMOS battery and reinstall
if restore button is there on motherboard means , press and release
remove processor and reinsert processor