Off topic: Aurora 100 motors don't spin up

I know it is off topic from the deviation view, but I hope somebody can help me:
I have the FrSky version Eachine Aurora 100, updated the BetaFlight fw to 3.1.7 and the BLHeli to 16.63, but the motors still don't spin up, just make some weird noise.
DShot600 is selected as the ESC protocol.
The values on the receiver tab do seem right, and the modes reflect the controls configured (the arm mode is selected too when I turn it's switch on), but still it doesn't react for the throttle just make that noise.
What am I doing wrong?

Thanks,
FDR

Betaflight is waiting channel values from 1000 to 2000. You need channels scale 125%.

Most likely you will need to reverse RUD and AIL for Frsky.

I've adjusted the rxrange of the first four channels, so in betaflight they read from 1000 to 1998 ATM...
Strange thing is, that even without arming the ESC start to make noise after about 10s.
There are other bad signs too: the rear LEDs, and the ones on the VTX do blink when the noise come.
Like if the voltage started to fluctuate...

Some more details: the quad behaves just fine, when it is connected through the USB.
I could even update the ESC fw.
It is wrong only when it is powered from the battery. It starts up fine, even the ESC tunes are there, but after 10s there is only a continuous random noise, and the strange flashing LEDs...

What sould I check?

Better battery?

The battery is brand new and fully charged, but I will try with an other one, thanks!

I'm more worried that it might be a hardware fault, for example the BEC, but the ESC board is quite expensive for just a try, not to mention that it is on backorder...

Probably it can be high battery voltage settings: min and warning voltage.

Where are they in BLHeli or in Betaflight?

Betaflight Configuration, Battery Voltage. With connected battery it show current battery voltage.

OK, thanks, I will check it this evening.

So I've checked the Battery Voltage configuration in Betaflight, and the strange thing is that it doesn't show the battery voltage in the config section, but it is shown up there on the header: it is 8.0V.
I tried to switch from ESC Sensor option to the Onboard ADC, but that hasn't helped...

BTW the Configuration is the default:
Battery Meter Type: ESC Sensor
Minimum Cell Voltage: 3.3V
Maximum Cell Voltage: 4.3V
Warning Cell Voltage: 3.5V
Battery Voltage: EMPTY!

My suspicions are justified: with the battery AND usb connected I can arm the quad, and the motors spin up, but without the USB they don't.
So I think the BEC is whether not connected or faulty...

Check power wires from ESC power wires to Minicube controller.

I've already checked, they are fine...

BEC placed at controller board, not ESC.

Yes, I know, thanks!
I've already contacted Banggood for replacement...

BTW this is what it does:

It looks like BEC working several seconds then died. Try to disconnect LED strip.

Yes, that's the next on my list, also I'll try without the VTX too.
If I let it rest for a longer period it will last longer, probably because it simply overheats...

Most likely it is VTX, it powered by +5V.

Also, you can get battery telemetry if you will connect receiver A1 or A2 pad to (+) power wire.

Wow, thanks!