About 30 minutes into a print, the printer stopped printing. It froze in one place and when I realised that it had gone awry, there was a large blob of PETG stuck to the nozzle, which I have since removed. The screen was unresponsive at the print page, not responding to me clicking the "pause" and "stop" options. I have turned on and off, both the power outlet and the power switch on the printer. Now when booting up, there is the normal animation of the boot up, but it is stuck on a blank page with the Anycubic Kobra. I bought the printer late last year and I think the firmware is up to date. The numerous previous prints have gone mostly smoothly.
What should I do now? Thanks in advance for all your help. (Apologies for the tag, as I could not find a more suitable tag)