I don't want this to be a novel but it sounds like you are interested in understanding a little more. I am not a trained tech, this is just what I have learned from reading the 1492 manual. 

I think those readings look fine, all you are looking for is a dead short.  If you look at the schematic of a 5184 it's 3 or 4 different circuits that monitor inputs which trigger an on/off state for power throughput. When the IC blows due to a bad situation it sometimes shorts one of those circuits or blows open. Usually when that happens you will find a diode or flyback with a hole blown in it. I just happen to know that I expect the ones I listed to read as a diode...if they don't something is wrong.  Same with the vertical IC, sometimes when they expire they short out. I have had both of these IC's pass a diode test but turn out bad. Same with voltage regulators, sometimes they test fine but they don't regulate. You learn how to watch for indicators.

Don't get too hung up on the details of each pin reading, you are really only looking for dead shorts at this point.

Do a diode test on the HOT (304), it should read as a diode from middle to each outside pin (.045 to .065-ish), just so long as it isn't a dead short. If it shorts from middle to either outside pin it's bad.

Still a chance the flyback is bad and there isn't any way to test that. The only option is to swap a known good one in. This flyback has a coil that sends voltage back to 5184 basically saying "I'm alive", I think it's pin 14 and if the voltage is too high it shuts down (Xray protection?) or if there is nothing for a period of time it shuts down. Unlike some other boards you cannot power this board without a flyback unless you use the low voltage bypass method covered in the manual.

Chris

Thanks a lot!

Just unsure of where to test the power supply.

Check the power supply output voltages, unplug and plug back in all the connections, make sure the boards are seated properly.

Good to know, do you have a recommendation?

Also, would you be able to tell me how to install a new one?

I appreciate all the help too.

Cheers

Those don’t last long and are know to corrode, destroying the board.