As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
BOI FLIGHT NR 2385: UPON PUSHBACK, FLAP POWER CAUTION LIGHT ILLUMINATED. FLAP HANDLE MOVED TO 15 DEG BUT NO FLAP MOVEMENT INDICATED ON FLAP GAUGE. RAN CHECKLIST, CAUTION LIGHT EXTINGUISHED. THEN RE-ILLUMINATED AGAIN AFTER SELECTING FLAP HANDLE. MAINTENANCE INTEROGATED CDS. FOUND HYD PRESS LOSS FAULT. REMOVED AND REPLACED FPU PRESSURE SWITCH IAW DH8-400 TASK 27-52-01-400-802. OPS CHECK GOOD. AIRCRAFT RETURNED TO SERVICE.