Fire Quantum QFlash 5Dr from 5D II

What do I need to fire a Quantum 5DR remotely in manual mode from a 5D II? What would I need to fire it remotely in ETTL mode?

The 5DR can be triggered by any radio trigger using a PC cable sync, or you can use the plug-in Quantum FW7Q radio receiver on the 5DR and trigger it with a camera based transmitter - FW9T.

To fire it remotely in ETTL add a D23WR TTL adapter to the FW9T on your camera.

If you don't want to use radio, the Qnexus plug-in for the 5DR will work with the IR signals from a camera based canon flash operating as a Master.

I tried firing one with NPT-04 flash trigger and had no luck. The light on the NPT-04 transmitter and receiver were going off, and they work on other flashes, so I know the NPT-04 is working. I also know there was no problem with the Quantum flash.

Did you try switching the HH plug around, sometimes the polarity can be wrong due either to cable, receiver or whatever ? Also check your shutterspeed is within normal X-sync range for the 5DII. I don't know whether this might affect the sync from the NPT-04, but it might.

Well, I take back what I wrote above. The T5DR comes with a cable that has prongs on one end and a plug that fits in to a hole on the side of the NPT-04 receiver on the other end. The NPT-04 transmitter does fire the T5DR when I use this arrangement.

However, the NPT-04 came with a PC Sync cable. Above the prong port on the Quantum, there is a small hole that the male end of this PC sync cord fits into. When I have the male end of the PC Sync cord plugged into this hole on the T5DR and have the other end of the cable plugged into the NPT-04 receiver, the NPT-04 transmitter does not fire the flash in this scenario.

Any ideas on why the arrangement described above does not work?

You can plug an earphone in that socket above the HH socket and hear the audio ready beep without annoying anybody, It's an earphone jack, not a sync socket. If your T5DR is new there should be an earphone in the box too.