ctfarmer Posted April 15, 2017 Report Share Posted April 15, 2017 I have a Garmin SL40 and has just experienced the following problem. During a flight, the Tx stopped working but the panel still displayed the dual frequencies. Prior to this issue the unit was working normally. I terminated the flight and started to troubleshoot on the ground. The following symptoms are evident. · Turn the power on using the circuit breaker or avionics switch and the dual frequencies display for about 1-3 seconds then fade or flash quickly away to nothing. · During the 3 seconds, the Tx appears to work until the unit goes off. · Once off as above, the unit has no working functions. · With power on the unit, using the units on/off control knob and nothing shows - the unit doesn’t turn on at all. · the head phones plugged in or unplugged, have no affect on the operation as above. I have measured 12+VDC on pin 1 on the RS232 connector on the cassette mounting plate. I have negligible resistance to the ground/earth on Pin 9 (power earth) back to the busbar located on the passenger side firewall in the cabin. I have not checked the resistance from there to the battery negative terminal but did tighten up the bolts. Everything else works fine connected to that ground busbar and will check further tomorrow. I suspect a ground or power issue but on the basis of the tests i have done, everything looks fine. I will set up a 3-4 amp load and load test from pin 1 to pin 9 measuring voltage at the same time. Anyone got any thoughts. Quote Link to comment Share on other sites More sharing options...
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.