Narrative:

We initiated a heading select turn per ATC request. While in the turn, several messages listed themselves on the MFDU. I attempted to disconnect the autoplt, only to find that I had already disconnected without alert. From that point forward, I hand flew the aircraft through touchdown. The MFDU alerts included: emergency dc bus fail, EFIS proximity southwest system inoperative, cabin pressure control channel, no automatic land. At the point of failure we also lost all radios temporarily, until alternate was selected, at which point we regained the first officer's radios. All electric panel indications were black. Cabin pressure control indications were off. Captain's pfd was blank until selecting alternate attitude/heading. We landed at chicago using alternate flap extension and 25 degrees as recommended. We came to an uneventful stop, using brakes only, as the reversers and lift dumpers were inoperative. Callback conversation with reporter revealed the following information: the reporter was the first officer and was flying the aircraft. The problem started about the top of descent into ord at FL310 and continued through rollout, a period of about 30 mins. The WX was severe clear, making life easier. No emergency was declared. The only action that the reporter knows was taken was to replace a heat sink in the dc power supply system.

Related reports:

Google
 

Original NASA ASRS Text

Title: AN ACR F100 SUFFERED AN ACFT EQUIP PROB HEAT SINK FAILURE THAT CAUSED A MULTITUDE OF ADDITIONAL PROBS, MANY ON THE CAPT'S SIDE.

Narrative: WE INITIATED A HDG SELECT TURN PER ATC REQUEST. WHILE IN THE TURN, SEVERAL MESSAGES LISTED THEMSELVES ON THE MFDU. I ATTEMPTED TO DISCONNECT THE AUTOPLT, ONLY TO FIND THAT I HAD ALREADY DISCONNECTED WITHOUT ALERT. FROM THAT POINT FORWARD, I HAND FLEW THE ACFT THROUGH TOUCHDOWN. THE MFDU ALERTS INCLUDED: EMER DC BUS FAIL, EFIS PROX SW SYS INOP, CABIN PRESSURE CTL CHANNEL, NO AUTO LAND. AT THE POINT OF FAILURE WE ALSO LOST ALL RADIOS TEMPORARILY, UNTIL ALTERNATE WAS SELECTED, AT WHICH POINT WE REGAINED THE FO'S RADIOS. ALL ELECTRIC PANEL INDICATIONS WERE BLACK. CABIN PRESSURE CTL INDICATIONS WERE OFF. CAPT'S PFD WAS BLANK UNTIL SELECTING ALTERNATE ATTITUDE/HDG. WE LANDED AT CHICAGO USING ALTERNATE FLAP EXTENSION AND 25 DEGS AS RECOMMENDED. WE CAME TO AN UNEVENTFUL STOP, USING BRAKES ONLY, AS THE REVERSERS AND LIFT DUMPERS WERE INOP. CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING INFO: THE RPTR WAS THE FO AND WAS FLYING THE ACFT. THE PROB STARTED ABOUT THE TOP OF DSCNT INTO ORD AT FL310 AND CONTINUED THROUGH ROLLOUT, A PERIOD OF ABOUT 30 MINS. THE WX WAS SEVERE CLR, MAKING LIFE EASIER. NO EMER WAS DECLARED. THE ONLY ACTION THAT THE RPTR KNOWS WAS TAKEN WAS TO REPLACE A HEAT SINK IN THE DC PWR SUPPLY SYS.

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.