DEVO 12s black screen

My transmitter arrive in bad.
After switch on, lcd is black.
Only uploader working after press TRN button for 2 sec.

I Try to upload deviation-devo12-v4.0.1.dfu and
devo12-lib.dfu lib files.
After upload only lcd screen switch on (blue screen), but entry (no characters).

I try to back the original fw to my devo 12s.
fw: DEVO-12 FWDT v1.5A.dfu
lib:DEVO-12 Lib v1.0.8.dfu
but, after reboot, again lcd is black.
And uploader working after 2 sec.

What is my DEVO's problem?

Could you help me?

Did you remember to copy the required files to the transmitter via USB after installing the firmware?

Was the screen blank when it was new out of the box? If it was, I doubt you have a deviation problem.

I try to copy files to the transmitter.
But, windows not show new device, not found usb drive.
I try to push ENT or EXT buttoon with power on, but nothing.

My bootloader is odd.

The bootload show if i push TRN button for 2 sec.
(TRN=Trainer, not ENT or EXT)
ENT and EXT is not effect.

I'm clueless.

I think: mzz bootloader is wrong or different.
My bootloader works differently.

The 12S is a little different than the rest of the Devo transmitters. The TRN switch is the one you activate for the bootloader, instead of the 'EXT' button. Your bootloader is correct.

When uploading the firwmare, make sure you use the 'Upgrade' button, not the 'Upload' button. The Upload button doesn't do what it's name implies. If you've used the 'Upload' button in the past, re-download the deviation firmware from the website before loading the firmware again.

Thank you.
I allways use UPGRADE. Never update. I read manual before use tool.

I don't understand what is the problem.
Screen allways black, execpt the upgrade screen.

I Think the china's GLB try to upgrade an wrong firmware/lib.

How to re-flash the bootloader, and low level files?

We use walkera/dfuse 1.7. with winxp.

Before upgrade, program show:
"Your device was plugged in DFU mode. So it is impossible to make sure this file is correct for this device. Continue however?"

This is normal?

I try to flash with an W7 x64. The problem not solved.

Thank you again,

It sounds like you're doing things correctly. From your first post it kind of sounds like it may have been dead out of the box, before you tried to flash deviation. If this is the case, you should probably return it for a new one.

I agree, if the screen was black when you got it new, when trying to turn it on, probably should have just sent it back ASAP.

What is the method, for full flash?
I think, flash the bootloader and so on.

The screen is good, working (i see it in bootload-er mode).
The processor good.
The flash good (if upgrade, and verify, then verify is ok.)

Any idea?
The return shipping cost to the goodluckbuy is very expensive.
And GLB is not an correct!!!