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Burned EFIS Display Boards

June 2022

The BendixKing EFIS 40/50 System Indicators are high-quality and efficient displays. As with any electronic component, periodic maintenance is required to keep the unit working effectively. With a little preventative maintenance these display units will continue to give trouble-free operation.


The ED 551/A Electronic Displays contain power supply boards that fail when not regularly maintained. Over time these boards can become damaged due to leaky capacitors. Left unchanged these capacitors will cause corrosion, begin arcing, and eventually burn holes in the printed circuit board. This damage is not repairable and a replacement board would have to be purchased at an estimated cost of $10,000. With high failure parts like these, preventative maintenance is crucial. Scheduled maintenance can catch this corrosion before it progresses and results in holes burned into the power supply boards.

Here at Duncan Aviation, we recommend that every 3-to-5 years the power supply capacitors be changed out, and the unit realigned and calibrated. This kind of preventative maintenance can save you from paying multiple thousands of dollars in repair costs and downtime.

Call a Duncan Aviation Components Customer Account Rep for details and pricing.