So yes the pins were all correct and I also soldered them to the board but the g30d / p dashboard only turns on once and then off again

So I connected the dashboard to the stlink as it says in the instructions for ble555 and removed the c2 from the back.
Then I connected the stlink to the pc and the dashboard lit up once and then went off again no connection.
All solder joints were firm

The problem is that when i connect the dashboard to my pc than its gos on and than off i need help