I work in IT and right now it’s a group of CCTV IP cameras that have a patterned flicker at certain times of the day but on random days. I’m pretty sure I’ve boiled it down to either a heavy power draw from other equipment or the shitty segregated network they’re on. I’m in the middle of desegregation and network uplift and the pool is shrinking so I might have it figured out finally but it’s been months still hella random.
I had something like this one. It was the ram. If I powered off, shut off the PSU and unplugged, then reseated the ram and tried again it would come on. Upgraded the ram and the issue went away.
Also, if you encounter this with a Dell laptop, same thing (just make sure to disconnect the battery before touching the ram).