The airport output circuit adopts the mu PC1498 integrated block, appeared a level bright line of the cause of the problem are: tafservice manual download site
 tafservice manual download site
(1) mu PC1498 integrated block crack of pin soldering causing poor contact. After replacement, then. tafservice manual download site
 tafservice manual download site
(2) mu PC1498 25 v power supply side 6 feet no voltage, the reason was that the 25 v power supply output D707 (FMISA4), R707 (2.2 Ω, 1/4 w) damage. After replacement, then.tafservice manual download site