DJM850-Wake up led flash.

Hello

I just replaced the motherboard of a DJM850.

When turning it on, the wake-up LED blinks 5 times, then pauses and blinks 5 times in a loop.

At startup, no message appears on the display.

I tried updating the firmware with the Windows app, but it says the cable isn’t connected. I’ve tried several, but it’s the same thing.

What do you think?

Thanks in advance.

Have a great rest of the day.

Best regards, Jack