What was found
GEAR DISAGREE RED WARNING MSG ON TAKEOFF GEAR UP GEAR REMAINED DOWN, PERFORMED QRH FAULT DID NOT CLEAR. INTERROGATED MDC HISTORY, FOUND B1-005968 ALL GEAR SYSTEM/ NO GEAR MOVEMENT. MADE MULTIPLE ATTEMPTS TO RETRACT LANDING GEAR WHILE ON JACKS, ALL UNSUCCESSFUL CONFIRMING DISCREPANCY. REFERENCE CRJ700 FIM 32-31-00-810-803, VERIFIED 28VDC PRESENT AT CONNECTOR V20P1 WHEN SELECTOR PANEL LEVER MOVED TO RETRACT POSITION. REMOVED AND REPLACED LANDING GEAR SELECTOR VALVE IAW CRJ700 AMM 32-32-10-000/400-801. PERFORMED MULTIPLE GEAR RETRACT/EXTEND CYCLES, OPS CHECKS AND LEAK CHECKS GOOD AT THIS TIME.