Thanks for the video, I have one of these or a very similar model -- It also seems to be a dead power supply.
Looks like it may have some display damage, but until I light up the display, I'm not sure.
Sadly it has some other physical damage to the RF in/out I may have to improvise a fix for out of semi-rigid coax and decent connectors. (Or see if Keysight is only asking reasonable prices for the part.)