Help with Qflash? (won't fire)

I just received a used T2 Digital flash from KEH and cant make it fire.

I'm connecting it to a Turbo battery that I've never used (it came with some other stuff...).but is clean and charges up quickly.

The flash turns on, all of the menus and buttons work (though the LCD light flickers).

But when I hit the test button, or try with a (tested and working) PC cord - no flash.

After about a minute, I get a 'check turbo' message. I turn it on/off. Same thing.

So where do I even start?

The battery appears to be working. But I don't really know.
The Qflash appears OK. But doesn't flash.
And the bulb in the flash (with the alignment dots aligned) looks good....

Any thoughts?

I am ignorant on this flash, but that the LCD backlight already flickers makes me think that it is already a very basic fault at the power supply, that either makes the flash not charge or effecting the flash control to an extend that it does not fire. (The firing control might be more complex than the classic trigger circuit.)

Ready light turns on?
Yes? it's an internal fault. No? It's still an internal fault.

^^^^^Couldn't edit this note but two things that come to mind are the trigger coil that bring voltage high enough to excite the main
flash tube or the tube itself has failed. Could happen.

A broken trigger coil would not make the flash go off indeed, but it would not make the display illumination flicker.

If you can, eliminate one variable - find someone else who has a known good battery for it and try it with that. If it still fails to fire, then the fault is with the head unit. If it fires, then it's your battery.