We have had a Garmin 430W in our aircraft for several years and it has become a treasured asset. Recently we began having problems with the display brightness. The problem is intermittent and all of the other functions seem to work fine even though the display does not. I would like to find out if others have seen similar symptoms and if so what the solution might have been.
* Several times, the display went to full brightness and contrast in daytime and became unreadable.
* Once, it went almost completely dark at night and also became unreadable.
* When it fails, the brightness changes gradually, not instantaneously, as if it was adapting to changing light conditions.
* When that happens, the brightness no longer reacts to changing light (e.g. covering the photocell does not reduce the brightness when it is at full bright, and shining a light at it in the dark does not increase the brightness).
* In each case, we were able to recover by switching the lighting from "auto" to manual and reducing/increasing the brightness and contrast values manually to a brightness and contrast close to "9999", their maximum.
* Restarting the unit in the air did not help (after restart, the unit goes back to "auto" lighting).
* However, after the plane has been sitting for a period of time the display operates normally for the next few flights.
* We have checked the avionics buss voltage and it is OK.
* We have checked the cooling air fan and it appears to be OK.
Thoughts, experiences, solutions, recommendations, etc. are welcome.
- larosta
* Several times, the display went to full brightness and contrast in daytime and became unreadable.
* Once, it went almost completely dark at night and also became unreadable.
* When it fails, the brightness changes gradually, not instantaneously, as if it was adapting to changing light conditions.
* When that happens, the brightness no longer reacts to changing light (e.g. covering the photocell does not reduce the brightness when it is at full bright, and shining a light at it in the dark does not increase the brightness).
* In each case, we were able to recover by switching the lighting from "auto" to manual and reducing/increasing the brightness and contrast values manually to a brightness and contrast close to "9999", their maximum.
* Restarting the unit in the air did not help (after restart, the unit goes back to "auto" lighting).
* However, after the plane has been sitting for a period of time the display operates normally for the next few flights.
* We have checked the avionics buss voltage and it is OK.
* We have checked the cooling air fan and it appears to be OK.
Thoughts, experiences, solutions, recommendations, etc. are welcome.
- larosta