What was found
PDX FLIGHT 2434 WINDSHIELD CONTROL CAUTION ILLUMINATED IN FLIGHT. PERFORMED CHECKLIST. PILOTS WINDSHIELD IS JUST BARELY WARM, CO-PILOTS WINDSHIELD IS COLD, ICE FORMED INSIDE. C/W FIM WINDSHIELD CONTROL CAUTION FAULT ISOLATION PROCEDURE PER TASK 30-40-00-810-805. CHECKED CDS FOR FAULTS, NONE NOTED. PERFORMED OPS TEST OF PILOT WINDSHIELD ANTI-ICING SYSTEM AND COPILOT WINDSHIELD AND PILOT SIDE WINDOW ANTI-ICING SYSTEM. ALL CHECK GOOD. NO CAUTION LIGHTS NOTED. NO PARTS REPLACED. AIRCRAFT RETURNED TO SERVICE.