Quote from @PimaxUSA - I was one of 17 who had issues with the first firmware and have no issues with the latest build I received:
Split from another topic about occasional black outs in 90Hz mode. This topic is about 90Hz mode causing the panels to be completely off from the start but everything else working (headset is tracked - seen in Pimax Experience window).
I have just ordered a new (standard) cable after finding out that I can make the headset completely power of by moving the cable near the plug at the headset end (and it stays off until I move it again).
Short update on the new cable: Still black panels (off) when choosing 90Hz but tracking fine (as can be seen in PE) and I’m unsure if there might be a loose connection in the headset as I can still make it power off/on completely by wiggling the cable gently (don’t want to keep doing it though as it seems to work better than the old cable).
With 90Hz on my 8KX the panels are always off when it is static and the led is red, but the tracking is always active. When I move it a little it takes a few seconds to turn on the panels and turn to green LED, so at first I also thought that the connection was failing. But I realized that it always reproduces, and if you leave static the HMD turns off at 45sec. more to or less. Of course in 75hz mode it doesn’t behave like this.
So perhaps moving the cable and turning on the panels could be that rather by the simple movement of the HMD it turns on but as it takes a while you think it is due to a bad connection.