As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
UPON STARTING ENGINES BOTH EFIS SCREENS EXHIBITED GHOSTING AND ARTIFACTS. AFTER A FEW SECONDS THE NUMBERS OF THE COMPASS CARD DISAPPEARED AND RED BOXES APPEARED IN BOTH SCREENS. REMOVED DPU P/N: 622-4682-004 S/N: 143CN AND INSTALLED DPU P/N: 622-4682-004 S/N: 813. ALL WORK DONE IAW COLLINS EFIS-84 IM P/N: 523-0775965 PAR. 2.7.7.1 F&G PAR. 2.7.7.2 PAR. 2.8.2. FUNCTION CHECKED GOOD. NO DEFECTS NOTED.