This is my 3rd landscape photographing season with DJI equipment, this time reinforced by mighty Matrice 200, X5S camera, Cendence and CrystalSky Ultra Bright. CS monitor is a key element of the system, as my iPad Air 2 couldn't deliver in bright summer sunlight. I mean, was a key element. Purchased months before and thoroughly tested successfully at home, failed the first day of filming in field. Poof, and the screen went black in the middle of flight, just like that. Glad we have this RTH button on RC ...
Naturally, as being on camping/boating trip in the middle of nowhere I have no chance to fix it or get a working replacement for the remaining portion of my expedition. Luckily I took my venerable iPad as well, but that's not what I was counting on ...

Edit: forgot to mention that I can't revive this unit, no matter what button I push. And no, it wasn't overheated. Rather chilly day, CS and controller in the shade of a tree ...

Sorry to hear that.  Despite CrystalSky being sold under Profesional as Pro Accessory; it isn't.  Failures without warning signs, and to many of.

First Cs-Ub I got (directly DJI) would hang without warning.
The replacement overheats, quits functioning, and does so without warning message.

As you say thankfully RC has RTH button.

Yeah I was seriously thinking about getting the UB, I have the 5.5" HB and it has been working fine since I've had it. I'm pretty sure if I do purchase another CS it will be the 7.85" HB not the Ultra. Many, Many posts about backlight failure(s) and situations like yours.

QuadKid Posted at 2018-7-23 01:59
Yeah I was seriously thinking about getting the UB, I have the 5.5" HB and it has been working fine since I've had it. I'm pretty sure if I do purchase another CS it will be the 7.85" HB not the Ultra. Many, Many posts about backlight failure(s) and situations like yours.

If your 5.5" HB is working fine - then highly suggest you stick with it!

Hopefully, DJI will soon have a Cs2-Ub.  With dual intakes, dual exhaust, and dual supercharged cooling fans.  Designed to work in Death Valley in July from High noon till supper time!