AFTER TAKEOFF, THE PLT RCVD TRAFFIC ADVISORIES FROM BURBANK APCH CONTROL TO PROCEED EASTBOUND THRU THE AREA OF BURBANK ARSA TO INTERCEPT V459. AT 1258:56 PST, RADAR SERVICE WAS TERMINATED & THE PLT WAS GIVEN A VFR TRANSPONDER CODE & TOLD TO MAINTAIN VFR FLT. ABOUT 45 SEC LATER, AN ELT SIGNAL WAS HEARD FOR A BRIEF TIME. TWO DAYS LATER, WRECKAGE OF THE ACFT WAS FOUND IN MOUNTAINOUS TERRAIN ABOUT 5 MI EAST OF THE BURBANK ARPT. ELEVATION OF THE CRASH SITE WAS ABOUT 1900'. AN INVESTIGATION REVEALED THAT WHEN RADAR SERVICE WAS TERMINATED, THE ACFT WAS FLYING EASTBOUND AT ABOUT 1900' MSL. SUBSEQUENTLY, IT TURNED LEFT TOWARD HIGH TERRAIN & COLLIDED WITH A POWER LINE CABLE, THEN CRASHED & BURNED. IMPACT OCCURRED AS THE ACFT WAS ON A NORTHERLY HEADING & IN A LEFT TURN. AT 1246 PST, THE BURBANK WX WAS IN PART: 1000' SCT, ESTD 3000' BKN, 5000' OVC, VIS 4 MI WITH RAIN, WIND CALM. ABOUT 1/2 HR LATER, THE WX AT BURBANK WAS: 600' SCT, 1500' OVC, VIS 4 MI WITH RAIN, WND CALM.