Epson ET-4550 freezes after two beeps, then turns itself off

What the title says. Today morning it would print one page, then beep two times, freeze and then turn itself off after a few seconds. Two hours later it would start, do a self-test (with a reminder to check ink levels, but they're fine), then beep two times, freeze and turn itself off again. Now it does the same after just a few seconds, can't even get to the factory reset menu. No error message whatsoever, Google turns up nothing useful either. It's a network printer but I didn't change anything, the error persists when it's disconnected from both USB and the network. Due to the ever-shorter intervals of the printer freezing I suspect an issue with the onboard power supply (tried different cables, same difference). Epson wants 260 € just to look at the %#*@ thing, and it's not even guaranteed they can/will fix it.

Do you think it's the power supply or a different problem altogether? I've found Epson error codes where the printer beeps three or five times, but not two times.