2007 E60 HUD stopped displaying speed
 

Hi everyone
Firstly I thought my HUD is broken completely, but when its cold, I get low temperature warning on my windshield so it is working. When night, I can see orange square on windshield, and when press HUD on/off button for 12 sec test normaly starts, but after the test is finished, again, only empty orange square is visible. Does it happen to anyone?