dromuald
Active Member
I have a GNS 480 in my RV-8. It sat in the hot sun all day at Airventure yesterday and I don't have a canopy cover. I imagine the cockpit got pretty hot given the sun was out and the ambient temp was in the mid to upper 80s. When I turned on my avionics master the 480 failed to boot up, there was no sign that it was even receiving power that I could detect. I reset the circuit breakers several times and cycled the power switch multiple times. Eventually it did boot up and operated normally. However about 15 minutes into my flight it failed again. I eventually got it to fire up and operate normally after about 3-5 minutes of cycling the power switch and CBs.
After the first failure I assumed the temp limit had been exceeded and that the unit has a self preservation logic to prevent damage. I notice in the installation manual that the operating range upper end is 55C or about 135F. It wouldn't surprise me if the avionics got that hot with the canopy closed all day. However when it failed the second time the unit should have been well below the max op temp.
I am now concerned that the unit may be defective, It did boot up properly once I landed and cycled the power but I have lost confidence in the unit. My home airport is in Class C airspace so I need comm to enter and get home. For now I am looking at purchasing and carrying a handheld transeiver and hoping it has the 10 mile range to talk to ATC.
Any advice, experience, or troubleshooting suggestions would be appreciated. I have been flying the unit for over 3 years since I purchased the plane and am otherwise very pleased with it. Given that the unit has been discontinued I am not sure how to proceed if it continues to fail. It is my understanding that the unit can still be serviced at Garmin, is that true? I recall it is a minimum $500 charge to open the box, and if it is an intermittent problem will they be able to accurately diagnose and fix it?
Thanks in advance
After the first failure I assumed the temp limit had been exceeded and that the unit has a self preservation logic to prevent damage. I notice in the installation manual that the operating range upper end is 55C or about 135F. It wouldn't surprise me if the avionics got that hot with the canopy closed all day. However when it failed the second time the unit should have been well below the max op temp.
I am now concerned that the unit may be defective, It did boot up properly once I landed and cycled the power but I have lost confidence in the unit. My home airport is in Class C airspace so I need comm to enter and get home. For now I am looking at purchasing and carrying a handheld transeiver and hoping it has the 10 mile range to talk to ATC.
Any advice, experience, or troubleshooting suggestions would be appreciated. I have been flying the unit for over 3 years since I purchased the plane and am otherwise very pleased with it. Given that the unit has been discontinued I am not sure how to proceed if it continues to fail. It is my understanding that the unit can still be serviced at Garmin, is that true? I recall it is a minimum $500 charge to open the box, and if it is an intermittent problem will they be able to accurately diagnose and fix it?
Thanks in advance