microair m760 "froze"

[gustavo_ercoupe]

Dear people:

 

The radio froze just after entering new frequency last week.

 

Froze at all, like "tilt", and not response to any command.

 

When I turn on the master lights of the airplane I see only a green display but not frequency , no number, nothing in display. And I want to know if to somebody here, happened it before.

 

I not have support here.

 

Sorry for my english!!

 

Have a nice day

 

Gustavo

 

Buenos Aires - Argentina

 

 

[Jabiru Phil]

Hi Gus,

 

I had a similar problem some years ago. Sent back to maker for a fix. They said it was an inside "dry" joint.

 

I now have two radios fitted, although no recent problems.

 

You could email Microair for advice.

 

PHIL.

 

 

[gustavo_ercoupe]

Hi Phill, thank you very much for the guidance.

 

I am shocked when radio was out of service, but I returned to the hangar and saw that it was very humid there. (Two weeks its rains a lot here)

 

I read carefully the post.

 

I'll get the plane's radio and bring it home, wait to dry and then try to connect. Maybe one technician can open it and seal it properly?

 

I will write to MicroAir too.

 

Thank you very much!

 

 

[dsam]

Hi Phill, thank you very much for the guidance.I am shocked when radio was out of service, but I returned to the hangar and saw that it was very humid there. (Two weeks its rains a lot here)

I read carefully the post.

 

I'll get the plane's radio and bring it home, wait to dry and then try to connect. Maybe one technician can open it and seal it properly?

 

I will write to MicroAir too.

 

Thank you very much!

Hi Gustavo,

 

Just to be understood correctly, when Phil said it could be a "dry" joint, he means that an internal solder connection inside the radio was not done properly during manufacture, and is possibly not making a good electrical connection.

 

The humdity in your hangar might add to this problem, but I just wanted to make sure there was no language problem to confuse you when Phil described a "dry" joint.

 

I hope you solve your radio problem.

 

Dave

 

 

[gustavo_ercoupe]

Thanks Dave !

 

I think I understand better now

 

Thank you very much

 

Gustavo

 

 

[frank marriott]

Interesting to see how different meanings can be taken from something when different languages are involved. When I read Phil's comment I didn't even consider a different understanding could be taken from it (Although after thinking about it, dry joint might be more of a "trade" term and reflecting my time spent as a radio tech. albeit many years ago).

 

 

[gustavo_ercoupe]

Yes Frank. this happens!! Sorry

 

Yesterday we were working on the radio.

 

We have found a fuse (type transistor) burned

 

I bought it today, and tomorrow we change it.

 

( I hope discover why It´s burned)

 

The fuse is 4A

 

I wrote a e mail to Microair and they said me can repair because it´s a "P" series.

 

In fact the "P" is one of the best radios (they said)

 

But I was thinking

 

shipping, taxes, cost repair ....

 

well I think it´s difficult sent the radio to Australia

 

We will try to repair this fuse and see !!

 

 

 

[Kyle Communications]

Have you got a schematic diagram for the radio so you can see where the failed component is in the circuit?

 

 

[jetboy]

Gustavo, you are probably better equipped than Microair to do the checks by the look of your workshop.....

 

I have done similar investigations on these radios and the transponders - look for solder shorted tracks Yes I have seen this happen on a unit purportedly only serviced by the factory.

 

If anyone can help with schematics that would be truly useful - to date the factory has not been cooperative so i still have a T2000 being used as a wheel chock

 

Kyle if you can help maybe the circuits could appear on Mods.DK or some neutral place

 

from memory, the transceivers series modulate the RF transistor, so the modulating transistor supplies about 6V to the RF final stage when in transmit and +-5V from that when speaking. If fuse is blowing only during transmit, that is the area to check

 

Ralph

 

 

[Kyle Communications]

Gustavo are you a amateur radio operator I see a few coaxes hanging out of the wall there?

 

I have circuits but only for a older model. I am not sure how much different the later ones are. Jetboy and Gustavo..send me a email to [email protected] and I will send you what I have. I will look at uploading them to Mods.dk

 

 

[gustavo_ercoupe]

Yes here we are, and we need a schematic diagram.... ( the new fuse burned too)

 

Now we are looking the regulator. Its a Lm2941

 

If someone have the diagram thanhs a lot !!!!

 

Working here !!!

 

 

[gustavo_ercoupe]

And now...

 

I' present you the new firstline

 

Im going to repair microair but, for sale it. (Or perhaps for com 2)

 

Firstline Its very similar

 

And the wiring as the same I think

 

Here some diagram and picture

 

 

 

 

 

[jetboy]

Gustavo, please report how the replacement radio (Flightline?) works out.

 

I have seen these available for a few years and they seem to be equivalent in most respects but lower price.

 

From your diagrams it looks like the intercom enable wire will need to be added like for an Xcom760 schematic

 

 

[gustavo_ercoupe]

Hi !

 

the microair finished his services (for now)

 

Yesterday I put the new "flightline 760" in the aircraft

 

the conector is the same and wiring diagram too

 

The flight line 760 t is a bit longer than the MicroAir, with which we must view the available space

 

but it work very well !

 

Atention ! You must to know something about flightline 760:

 

its lower price but the radio haven´t papers or forms, nothing to present !

 

If you have a experimental aircraft not problem, but if you have another inscription I suggest you consult

 

I miss the microair, but in a future I m going to have again!