SWITCH No WLAN find no signal

Hi i need help with two SWITCH. I life in Germany and have a repair service. Now i have the third SWITCH with the same symptom. The console find no signal. Near the Router is the same. What i have do: reballt the broadcom chip, changed the broadcom chip, reset the switch, updated the SWITCH manualy and nothing helps. All three switches the same Symptoms!!! Does any a solution for me? Or does someone fixed this issue…?