What was found
BOI FLIGHT NR 2311: GNS1 DESELECTED, RAN CHECKLIST, RESELECTED. OK FOR 3 MINUTES. LATER DESELECTED AGAIN. RAN CHECKLIST AND WORKED FOR 9 MINUTES, THEN DESELECTED. THEN 5-10 MINUTES LATER, GNS2 DESELECTED. SAME PROCESS REPEATED. THEN IRS DESELECTED 5 MINUTES LATER. FMS WENT INTO DR MODE. 2 MINUTES LATER, DR MODE WENT AWAY. MAINTENANCE CYCLED AIRCRAFT POWER. ALL INDICATIONS NORMAL. GNS1, GNS2 AND IRS ARE SELECTED AND ALIGNED WITH NO DEFECTS NOTED. NO PARTS REPLACED. AIRCRAFT RETURNED TO SERVICE.