One more thing if you already tried this but didnt work then try method
1.connect your pc to internet
2.open flash tool load every file as given in the tutorial
3.click on download
4.connect your phone to pc
5.in few seconds it will show brom cmd start fail error
6. As soon as it appears click ok and in a second again click on download.
This helped me ,,Good luck

Well... thanks for all the advices given to me.
But of course I had to f*ck up something...
I think I flashed wrong something and phone died, it doesn't react to buttons and I cannot get into fastboot mode.
It is still available to flash all partitions except secro and preloader, if I try to flash them I get error:
STATUS_SEC_DL_FORBIDDEN (0xC0020004).

Atm I can't find any way to flash it,
I keep looking but still nothing :/

There is currently (reportedly) only one way to fix your phone and that is by disassembling the device and removing the battery for 10 minutes. If only the BROM of your phone is malfunctioning then this will fix the issue and you'll be able to flash a recovery on your phone with this tutorial https://forum.xda-developers.com ... -note-hard-t3682743 However, if your PC/Laptop still fails to detect your phone then you're done because it will be  a problem with the eMMC of the device and it's very hard to fix for normal users. Software boxes won't help you here because the preloader of your phone is damaged hence why the pc can't detect your phone properly.

Hi guys,
I am sorry for not answering for so long.
Thank you for all of your messages and help attempts but the problem is now solver.
I've sent my brick to service center and they have managed somehow to fix it.
Thank you one more time for participation.
Due to problem being solved I think this thread can be closed.

when your flashing doesnt succeed try that:
keep pressing side buttons (v+ , v-, and power) all together. until it restarts when usb is connected and sp tool download clicked.
it worked for me

one another thing : this a must
+ first of all before you start these drivers must be installed correctly:
MediaTek USB Port
MediaTek Preloader USB VCOM (Android)
MediaTek DA USB VCOM (Android)
use USBDeview.exe for uninstall driver . after than reinstall it. windows making mass with this drivers. or try it on another pc.
+ than try the all steps again and again.
if it doesnt flash keep pressing three side buttons at the same time and hold it untill it restarts (usb cable was pluged.). it flashed. than i succeed.

i used Kirpitch.M3Note modifed sp flash tool to flash my firmware. it has both for m and l models flyme 6 support.

Wait, are you trying to tell me that all I had to do to make preloader flashable was to hold all the 3 buttons?
The phone was dead, it didn't respond to power buttons, so I wasn't able to get into fastboot or recovery.
Would it still work?

BROM ERROR : STATUS_BROM_CMD_SEND_DA_FAIL (0xC0060001)  err

I am getting the same error
any solution available?