Electrical Problem - Main Circuit Dead

[Steven]

Thanks for the suggestions. I'll check out the configuration for those items the next time I'm at the plane.

 

Steven

[Steven]

Thanks Roger,

 

I didn't even know about the screen rotation and should have checked the Pilot's User Guide. That was the problem. The boot screen had been changed to a split including the HSI (AUX) data. I changed it back to EMS/FUEL and now all is well ..... almost.

 

I took the plane for a flight today and only 2 minutes out of Westchester Airport (HPN class D under the NY class B shelf) the tower radioed me that they couldn't see my transponder signal. I rebooted the Garmin GTX 330, but to no avail .... nor did "IDENT" and a discreet squawk code allow the tower to see my signal. I had to return to the airport, glad to have flown again for the first time in a few weeks, but disappointed that it was only for a few minutes and that yet another gremlin has been at work on my plane. Why do all these gremlins seem to love my plane so much ? haha.

 

Does the missing transponder transmission sound like an antenna problem or the cable to the antenna ??? Should I check the antenna, perhaps for a loose connection ? Is it underneath the plane ? It seems to me that transponder problem is unrelated to my prior electrical problems, but maybe I'm under a misconception. Any suggestions ? It boots up just fine although the flight level info is missing. I understand that the unit does a self test at every boot up and there's no error message.

 

Steven

[coppercity]

Might try re-seating the unit in the tray first, there is a small Allen wrench like 3/32 screw inside a hole in the front of the unit. You unscrew that all the way til it stops, which rotates a tab connected to it. It's captive so it won't come out. Slide it out of the tray, then slide it back in, tighten that small screw again until it's tight, it should pull the unit in the last 1/8 of an inch. If that doesn't do the trick check your antenna connection inside the center tunnel belly area.

[Brucegoose]

Agree with you totally Eric, happened to me except found cable had come out of the bnc connection, refitted and tightened properly and slid the GTX back in and retightened,all back to normal.

 

Regards

 

Bruce

[Steven]

Thanks Eric and Bruce for the suggestions -

 

When I unscrew that tiny screw, will the entire transponder unit slide completely out of the panel so that I have access to the back of it ? I'd like to be able to check the BNC cable connection. Or do I need to remove the entire avionics panel to do that ?

 

I was also wondering where the transponder antenna is located. Is it the rounded dull blade that sticks out from the belly of the plane ? Maybe I should check the BNC connection there as well.

 

Thanks,

Steven

[coppercity]

Hi Steven

 

When you unscrew that tab the transponder will slide out of its tray a 1/2 inch or so then you can grab it and slide it all the way out. At that point take a look at the back of the unit, make sure all the contacts look clean. Then look inside the tray at the BNC connector at the back of the tray, if you can see the center conductor there then it should all be fine. Slide the unit back in and tighten down the same screw, make sure the unit seats all the way.

 

Your Transponder antenna is the little shark fin on the belly below the cockpit, you can access it thru the center console panel aft of the throttle quadrant. Four screws and that panel lifts off. You will see the BNC connector for that antenna above a small aluminum ground plane in the belly.

[Steven]

Thanks Eric for that detailed description .... I plan to be at my plane again later this week and will do as you described.

 

Steven