I picked up a used Siglent SPD3303X-E power supply from Ebay, which I thought I was getting a reasonable deal on, but it's not booting. On searching, I saw some of the other firmware-related boot issue posts, but they sound slightly different than what I'm seeing. When I power it up, all the buttons light and the display comes up with the Siglent splash, but it only stays lit for a second, then goes dark. It cycles back on about every 3 seconds. At the same time that the display lights up, all the lit buttons flash brighter for just a fraction of a second. I've let it loop like this for several minutes, and it doesn't every seem to go past this state. Anyone have any troubleshooting thoughts? My initial guess would be power, but I haven't cracked it open yet to see what's going on.