My brand new Raspberry Pi 4 Model B 4GB RAM from Raspberry Pi 4 Computer Desktop Kit worked excellently for 1 hour and I updated it using sudo apt update and sudo apt dist-upgrade, rebooted and put in the temperature monitor in the panel (about 68 degrees, ambient temperature 25 degrees) and surfed for 34 minutes using Chromium, and then it died (i.e. the screen went into power save) with a snapping sound - probably from the speakers. The Power LED (red) went dim. I pulled out the cable and also the AC adapter and waited, but when I connect it again it doesn't show on the screen and the power LED is just dim.
I have several Pis since 2012 and all still works. This Pi 4 is the first that broke.
I used all the original equipment except for the screen and speakers, but I have used them for several years with my Raspberry Pi 3 and the Pi 3 still works with them. I use an adapter from EU to UK power connector that I have used for several years with another thing and it still works with that thing. The screen uses an HDMI to DVI-D adapter. I don't have any other USB-C equipment, so I can't test if the original Raspberry Pi AC adapter for Pi 4 still works, but my guess is that it's nothing wrong with it. It's probably the power part in the Pi 4 that is broken.
There is usually never any power surges here and and the Pi 3 and Pi 2 next to it was running and were not stopped, so I don't think there has been any power surge. I bought the Raspberry Pi 4 Computer Desktop Kit on The Pi Hut and they shipped it to Sweden so it's rather difficult to return it. It would be good if I could exchange the Pi 4 with your local partner e.g. Electrokit instead of sending it back to the UK by mail. The reason I bought it from UK is that they don't sell Raspberry Pi 4 Computer Desktop Kit here and I preferred the UK keyboard before the US or the other language models, and then I got the UK AC adapter.
I put the microSD card in a USB adapter and plugged it into a USB port of a Raspberry Pi 3 and that was not broken, and all partitions showed in File Manager.
I do have a multimeter so I might measure voltages on the board or on the pins using cables, if that could help.