[NAME] nasif  Dell does not support using a raw board in a non dell case.  You did attach some of the cables from the old case because your error does not look like the pics below. Dell Optiplex 790 & 990 and Precision T1600 Front Panel Header Adapter Kit[URL] You also need fan adapter  Dell fan adapter to standard pwm   T1650 Owners Manual   [IMAGE] [IMAGE][IMAGE][IMAGE]
İ have error screen  With this information  ![IMAGE]Alert rear fan failurei    İ Have buy the new empty case gaming but i want to disable this screen         
Dell t1650 error screen