As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
CO-PILOTS PFD WOULD NOT DISPLAY ANY FLIGHT INFORMATION. IT WOULD ONLY DISPLAY RED X. YOU COULD GET THE FLIGHT INFORMATION IF YOU REVERTED THE DISPLAY TO DU 3. CYCLED DU4 C/B DISPLAY NEVER RECOVERED STAYED BLANK REPLACED DU 4, LOADED OPS S/W IAW MM, 34-23-10. OPS CHECKED DU4 GOOD IAW MM 34-23-10.