What was found
DUIRNG CRUISE, LEVELING AT 37,000 FT THE CREW RECEIVED STABILIZER, MACH AND PITCH TRIM MESSAGES. UNABLE TO GET STABILIZER CHANNELS ONE OR TWO TO RE-ENGAGE. QRH PROCEDURES WERE COMPLIED WITH AND AN EMERGENCY WAS DECLARED AS A PRECAUTION. THE AIRCRAFT LANDED SAFELY IN DFW. MAINTENANCE REMOVED AND REPLACED THE STABILIZER TRIM ENGAGE SWITCH. OPERAITONAL CHECKS GOOD. AIRCRAFT OK FOR SERVICE. (M)