What was found
ACFT HAD AN IN-FLIGHT TURN-BACK DUE TO DISPLAY SOURCE FAILURE ON FLIGHT APPROX WAY, CREW REPORTED A DISPLAY SOURCE MESSAGE ALONG WITH LOSS OF HYD "A" SIDE INFORMATION. CREW ALSO REPORTED MOMENTARY LOSS OF AIRSPEED AND ALTITUDE INFORMATION ON THE F/OS PFD. ALSO HAS A WEATHER RADAR RANGE DISAGREE ALERT, WHICH MAKES THE WXR INOP AND IT WAS REQUIRED FOR THE APPROACH. ALL ISSUES CONSIDERED IT WAS DECIDED TO TURN THE ACFT BACK. SNAG INFO: PILOT SNAG G 36059, DEFECT: IN CRUISE AT FL 360, DISPLAY SOURCE FAILURE ON CAPT/FO PFD, LOST SPEED AND ALT INFO F/O SIDE AND F/D BARS, MASTER CAUTION ENG NR 1, HYD INFO BLACK, NON NORMAL CHECKLIST AND RETURNED. REPLACED NR1 DEU IAW MM 31-62-21 SOFTWARE OPC 3169-BCG-00V-CB LOADED IAW 31-62 -21 NO FURTHER FAULTS PART REPLACED: PN 4081600-930, SN 31836440. THE SDR WILL BE UPDATED WITH TEARDOWN INFORMATION ONCE AVAILABLE.