What was found
EWR---CO3869, CREW REPORTED, "AFTER T/O. LDG SELECTED UP. NOSE GEAR FAILED TO RETRACT. CYCLED GEAR AND MAIN GEAR FAILED TO RETRACT. CYCLED GEAR A SECOND TIME AND ALL GEAR FAILED TO RETRACT. AIRCRAFT AIR RETURNED TO EWR AND LANDED UNEVENTFULLY.....MAINTENANCE TROUBLESHOT SYSTEM AND REMOVED AND REPLACED LANDING GEAR LEVER CONTROL IAW EMB145 AMM REFERENCE #32-32-02. OPS.CHECKED GOOD IAW EMB145 AMM #32-32-00 ALSO, REFERENCE M-602 #513174. AIRCRAFT RETURNED TO SERVICE.