As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
ASH 6555 DEN-PHX. ABORTED TAKEOFF FOR GLD UNSAFE MASTER CAUTION MESSAGE. MAINTENANCE INTERROGATED THE MDC AND IT FLAGGED THE NR 1 RADIO ALTIMETER. MAINTENANCE PLACED THE RADIO ALTIMETER ON MEL AND NO FURTHER DEFECTS WERE NOTED. MAINTENANCE RESECURED LOOSE RAD ALT PLUG AND OPS CHECKED GOOD.