Honestly, sounds like your power supply (PSU) may be going bad.
i tried with a different external power adapter (apparently my old dell inspiron laptop has a same adapter), but result is the same. previously when i used the original cpu of this machine, it sometimes will hang during the dell logo screen, but never goes to black screen. external power adapter is 65w. screenshot is the specs of my cpus (left is the new. right is the original). it doesn't bother me too much with this issue, but zino is for the elder to use.