What was found
R(FO) MCDU OCCASIONALLY BLANKS, THEN PAGE RETURNS WITH ABOUT HALF THE CHARACTERS MISSING AND SOME APPEARING GRAY. FULL PAGE RETURNS WITHIN A FEW SECONDS. MCDU CAPABILITIES (E.G. SELECTING VREF ON INT/REF PAGE) WORK NORMALLY. GROUNDED - YES. PER B737-900 FIM 34-61 TASK 804. RECYCLED MCDU C/B. MCDU WORK NORMAL. PERFORMED GOOD CDU LAMP TEST REF B737-900 AMM 34-61-01-710-801. MCDU LCD SCREEN WORK NORMAL.