Garmin 430 VLOC fault

[aviofreek]

Hi guys,

I came accross a fault on G430, so I was wondering has anyone ever experienced something similar...

VLOC side of G430 is paired with panel mounted course deviation indicator and it used to work like a charm. When all of a sudden it decided not to work anymore. The owner says, that they did nothing to it that would result in this situation. He even had some avionics people taking a look at the wiring/hardware side of it and they found nothing wrong.

I believe it's software problem, but not sure, as yesterday I switched it ON and it actually went through the self test once (needles half up/half right, no flags), but upon restarting went back being U/S.

Also, as he bought the airplane a few years ago with the radios installed he never got/bothered to get any other G430 paperwork/software from the previous owner..

Advices?

[Check Airman]

Not an avionics person, but I'm quite familiar with the 430. What exactly do you mean by "it doesn't work"? That's pretty vague.

[aviofreek]

Both warning flags on CDI paired with G430 visible, no needle movement either. Not even on the self test portion of the start up. Also seems to be intermittent, as a few days ago when I switched it ON, it went through the self test (needles half up/half right, no flags in view). Upon restarting went back being U/S...

Sorry for not being clear on the defect in the first post

[Check Airman]

If it's failing the self test, I'd think that the avionics guys should be able to fix that. Does the OBS on the screen respond when you twist the OBS on the VOR receiver? I'll admit that I have never seen the unit fail the self test.

If it's intermittent, perhaps something is loose and the vibration is causing the problem to come and go?

[Oktas8]

Not to be insulting, but to clarify that it's not the most obvious problem:

Have you tried cycling the CDI push button on lower left of the G430? Does that change the situation?

[Check Airman]

You know what they say, always check the obvious first.

The CDI source shouldn't matter during the self test though.


On checking the obvious...

The story goes that a crew at my airline that had to make a maintenance log entry after an engine failure (with the associated EICAS message) at the start of the takeoff roll. The subsequent investigation revealed that the second engine had not been started!:D

[wigglyamp]

If the CDI goes through the self-test correctly but it always flags when used for real, look at the NAV antenna system. If the aircraft has 2 Navs, chances are they share the same antenna via a coupler so if only one is failing, it could be the coupler or the cable from there to the GNS430 rack.