GE Speedtronic Mark VI control system has been powered down for almost a year. It was powered up recently. the Controllers (R, S & T) weren't in sync initially. a VPRO card & VCRC card on Controller S were replaced. The Controllers are now in sync and have been pinged, data is being received via network switch. But there is no communication on the HMI (Black screens are being displayed where the datas are to be seen.

Kindly advice on way forward

 

try to check the cat6 cables is correct and not sawiped somehow.

try to stop and start the project.

try to restart the hmi.