3.4.38 ―c4‖ ODU Jumper Cap Error 
Error display: ODU mainboard, IDU wired control and IDU receiver light board will display c4 
Error judgment condition and method: 
If jumper cap model doesn‗t match with mainboard, report the error 
Possible reason: 
■Jumper cap is not installed 
■Jumper cap model is wrong 
■Detecting circuit is abnormal 
Troubleshooting: