What was found
(CAN) SHORTLY AFTER LEVELING OFF IN THE CRUISE AT FL 240, 18 MINUTES IN TO THE FLIGHT, THE CAPTAIN`S PFD DISPLAYED IAS FAIL, ATT FAIL, IVSI FAIL, TCAS FAIL & HDG FAIL. QRH DRILL WAS ACTIONED FOR ATT FAIL & THE EFIS ATT HDG SOURCE WAS SELECTED TO NO 2 SOURCE, FIRST OFFICERS SIDE. THE CAPTAIN`S PFD CONTINUED TO DISPLAY THE ABOVE WARNINGS WITH NO REVERSION TO NORMAL PFD SYMBOLOGY, ONCE THE NR 2 SOURCE HAD BEEN SELECTED. QRH DRILLS FOR THE OTHER FAILURES DISPLAYED WERE ALSO CONSULTED WITH NO POSITIVE EFFECT. AS DETAILED IN THE QRH THE ACFT WAS SLOWED TO 200KTS. A/P, Y/D & ALT SEL FUNCTIONS, ALONG WITH ALL OTHER NORMAL AFCS FUNCTIONS REMAINED OPERATIVE ON THE FIRST OFFICERS. UNSCHEDULED LANDING COMPLETED. ENGINEERS SWITCHED CYCLED PFD ON & OFF BUT DATA REMAINED THE SAME. THE IOP 1 CB WAS TRIPPED & RESET. ALL DATA RETURNED TO NORMAL.