What was found
MLG DISAGREE, ONLY NOSE GEAR INDICATING DOWN, RAN QRH PROCEDURE, PULLED LANDING GEAR MANUAL RELEASE HANDLE TO DEPLOY GEAR, GEAR DEPLOYED WITH MANUAL RELEASE HANDLE. (FLIGHT 4674 - FILED CLOSED)ARRIVED AT AIRCRAFT AND INTERROGATED PSCU PLEASE SEE ATTACHED FILE FOR CODES LISTED. AFTER CLEARING IN REF TO CRJ 200 FIM 32-60-07. PSCU PERFORMED A SYSTEM TEST AND RECEIVED CODE DO_43?. FDR DOWNLOAD WAS C/W WITH HAVING FINDINGS OF ALL GEARS RELEASED FROM UPLOCKS BUT ONLY NOSE GEAR EXTENDED DOWN DURING NORMAL EXTENSION. MLG UPLOCKS RELEASED AT COUNTER 1103453.0 AND THE NLG UPLOCKS RELEASES AT 1103455.0. THE NLG DOWN LOCK ENGAGED AT COUNTER 1103463.0 AND THE MLG DOWNLOCKS NEVER ENGAGED. AT COUNTER 1103482.0 IS WHEN THE GEAR DISAGREE WARNING HAPPENED. PERFORMED GVI OF LG HARNESSES AND SENSORS AND FOUND NO OBVIOUS DAMAGED. PLEASE REF EAML 1788364 FIR DEFERRAL OF LANDING GEAR EXTENSION SYSTEM.