Narrative:

Before takeoff, master caution reset light would not go out. No segment warning lights were on. I flew 1 1/2 hours before reporting this to maintenance. (This was a short caused by water.) the segment lights were working properly.

Google
 

Original NASA ASRS Text

Title: ACFT EQUIP PROB NOT WRITTEN UP IN LOGBOOK AT TIME OF DISCOVERY. FLT OR FLTS MADE BY ROTARY WINGED ACFT WITH MASTER CAUTION RESET LIGHT STILL LIT.

Narrative: BEFORE TKOF, MASTER CAUTION RESET LIGHT WOULD NOT GO OUT. NO SEGMENT WARNING LIGHTS WERE ON. I FLEW 1 1/2 HRS BEFORE RPTING THIS TO MAINT. (THIS WAS A SHORT CAUSED BY WATER.) THE SEGMENT LIGHTS WERE WORKING PROPERLY.

Data retrieved from NASA's ASRS site as of July 2007 and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.