Increasing the Life of the DU-870: Preventing CRT Burn-In

March 2014

DU-870 is a display unit in the Honeywell Primus System installed on several make/model aircraft. It can be used as a primary flight display (PFD) and multifunction display (MFD) interchangeably.

Over time, it is not unusual for the CRT to experience burn-in caused by the continual bombardment of electrons from the CRT’s guns on one spot of the CRT screen. This is why screen savers were widely used in the old CRT monitor days. The screen saver applied a continually moving image as to not let one area become burned.

However over time and general use, the CRT will become dim and possibly fail the overall brightness characteristics required in order to be returned to service. At this time, the CRT requires replacement.

Many operators have found success in increasing the life of their DU units by sending in the LRU for internal cleaning of assemblies and cooling fans to help prevent heat build-up. Also, rotating the DUs from side to side or MFD to PFD. Keeping the DU brightness turned down can also increase its useful life.

Other Common DU-870 Squawks include the following:

• Totally Inop
• Intermittent Blanking
• Dim Display or Fuzzy Display

No Bill Back Exchange

Duncan Aviation can provide NO BILL BACK exchange units, including core units that have bad high voltage power supply and if the CRT has screen burn in. These units come with a one year warranty.

With several overhauled units in stock, these are available today. For more information call a Duncan Aviation Rotable Manager at 800.228.1836 or 402.475.4125.