Ender 5 Pro not responsive screen blank

Hello, I am having an issue with my printer after I had a failed print. The hot-end became a ball of PLA as a result of the failure. I rescued the nozzle and removed the blob before it cooled. I had to cut the thermistor and heating element wires out of the mess. I replaced the thermistor and heater but once I reconnected the new items and rebuild the now clean hot-end, the screen no longer works and the printer doesn’t show up as connected in Octoprint. I think it is the power supply or the board that has malfunctioned but I am not sure how to diagnose or recover the functionality. I also tried adding the firmware to the SD card and rebooting but no change. The fans spin up on power up but the CR touch flashes and extends and retracts its probe seemingly randomly. Any suggestions would be welcomed. I hope I don’t have to replace the card or power supply or both.

I just saw this posted elsewhere regarding the Ender 3:

What happens if you disconnect the USB connection to the computer/rPi that is running Octoprint?

Thanks for the reply. I unpluged the PI and same issue still unresponsive and a blank screen.

Then I’m guessing it’s the controller board - can you test that for operation or try to swap in a new one?

You mentioned that the BL Touch flashes. Do you mean it is constantly flashing (red) on and off or just between red and blue when you first power up the printer? If it’s flashing red/blue when you first power up, and the pin drops and retracts, that is normal, but flashing on and off is not. As for your power supply, Kersey Fabrications did a video a while back about replacing his power supply after it gave up the ghost. His E5+ and mine as well, both shipped with a 350 watt PSU, mine was a MeanWell, and his was a cheap off brand. He sent his video to Creality to show them what he did and why, it’s a very worthwhile video to watch. I did the same 600 watt PSU swap that he did immediately after watching it.

Your fans and the LCD are powering up. That makes me suspect the mainboard. Also, this sounds a lot like a problem I had some time ago:

I ended up replacing the mainboard.