MGL Avionics User Forum

Hello all.

Wondering if anyone else has experience a failure with their V16.

We just lost our 2nd V16 today. The plane came with a V16 when we bought it and that one failed after about 3 years (according to the installation date in the log). We replaced it with a new V16 and that one failed today at just under 3 years of age.

We have good voltage on pins 24 and 25 (~13.5v) and are using an AVIOGuard on the buss. But the power LED is no longer on and the Razor says "COM device not available". It just popped up mid-flight when we tried to change the channel.

Thanks

Mine failed after 360 hours and 2.5 years.

Worked perfectly since new and all of a sudden got big red X on EFIS! Had just landed and had turned onto taxiway and went silent..

Red warning on VEGA…”radio no connected”.

Pulled panel. Green light not on. Checked connector. Had 12,5 volts on pins 22/23 & 24/35. Connected a 3 amp load and load worked fine.

Contacted Adam. Pretty sure radio failed

Take one of the two end covers off (two screws) so you can slide out the PCB (the entire radio is on a single PCB).
Very close to the D25 connector you will find a small component marked L42 (if you look towards the D25 socket its on the left side).
In most cases we have so far seen this component blows (you can see it is damaged).
This is a small high current ferrite inductor that serves to prevent RF from entering the radio ground - it's wired in line to the two ground pins on the D25 connector. It also acts as fuse in case current exceeds 5A on the ground. There are multiple ground points on that connector so if you have a ground fault (or bad ground wiring as such) on your aircraft it is possible to send a large current through the radio (usually from one of the audio or other grounds to the radios power supply ground) - this will blow this component.
Replacing it fixes the problem. It is a 5A (or higher rated) ferrite in an 0805 package. You can also consider simply replacing it with a wire bridge but you will loose the effect of blocking RF (in our experience the difference is not noticeable anyway). You can also consider replacing it with a small fuse in the same location to preserve the ability of the radio to protect itself. If you replace with a wire and you do have a ground fault - next time it will burn ground tracks and that may not be easily fixable so be sure that you do not have any condition that can send high currents through the radios grounds.

Note that a secondary possibility to blow this item also exists - the radio has a reverse biased diode at its input in order to shunt any negative voltage spikes so they cannot cause harm (you get these mostly from solenoids, engine starter motors etc). If the negative voltage persists with too much current flowing for too long in reverse direction the inductor L42 will also blow - it's cheap insurance for the rest of your radio as it protects the expensive parts from damage.

Have a look...

Rainier