What was found
PDIS 967 27-80 8802 24JUL23 DTW FACT U AFTER TAKEOFF, AFTER FLAP INDICATION WAS UP, PASSING APPROX 4000 MSL, AN AMBER LE SLAT ASYM POSTED. NO ROLL ASYMMETRY OBSERVED. COMPLIED WITH QRH. DECLARED EMERGENCY ON APPROACH. FACT 24JUL23 16:53 DTW U AMM: 27-81-42-4 AMM: 27-81-00/501 REMOVED & REPLACED R/H OUTBOARD LEADING EDGE SLAT LOSS SWITCH. PER B757 M.M. CHP. 27-81-42-4. PREFORMED OPS CHECK PER B 757 M.M. CHP. PAGE BLOCK 27-81-00/501. OPS CHECKS GOOD.