What was found
LANDING GEAR WOULD NOT RETRACT AFTER TAKEOFF WITHOUT PULLING MANUAL OVERRIDE TRIGGER. ONCE GEAR WAS UP AND OFF, ALL GEAR LIGHTS EXTINGUISHED, BUT TAKEOFF WARNING HORN WOUND NOT STOP. ON ARRIVAL, FOUND PSEU LIGHT ILLUMINATED WITH LATCHED UNRESETTABLE FAULT 31-51001, "GSBV CL FAULT", TROUBLESHOT IAW FIM 32-61, TSK 825 & FOUND GSIV PROXIMITY SENSOR AT FAULT. R & R OPS CHECKED GOOD, FAULT NOW CLEARED, OK TO CONTINUE.