Ezuhf TX overheat, wont turn back on

[j5coat]

I have been flying with my ezuhf for about a week getting everything setup. I have it on a 9303 72mhz version hooked up through the pins in the back, not the trainer port. Yesterday i was out flying with 2 successful flights and on the third my ezuhf transmitter would not turn back on, i have been powering it through the tx battery but also tried to power it via the dc in with a 3s lipo. I packed up and came home, after about 30 minutes i tried it and it turned back on.

So today i went back out to test it with some hovering around everything was fine again through the first pack, turned everything off and then it would not turn back on. Brought it home put it in front of a fan and in 3 minutes it turned back on.
Both times i was running in low mode, both times i tried to power it using a fully charged 3s lipo, and it still would not turn on. has anyone ever had this problem?

[j5coat]

View this video on YouTube

Here is a video i made of my problem. The screen is normal that just the way the gopro picks it up, everything is fine with the screen on the 9303. The radio is on the whole time except when I sit it in front of the fan. In the beginning of the video I bring the unit in from outside, It was on for about 8 minutes out there, I turn it off and then try and turn it back on, the ezuhf will not turn on after its heated. (skip to 2:00 ) So i set it in front of the fan, I turn it on after 2 minutes or so in front of the fan. Now that it cools a little bit it will turn back on, take it back outside and turn it on low and let it sit there for 7 min ( my flight time on the quad ) (skip to 9:30 ) now that its warm again I turn off the radio then back on and the ezuhf does not power back up. ( skip to 11:20 ) after sitting in front of the fan again it powers up.

[Scotttu]

Cool dog! He's just following you around

Obviously a heat related issue in the power supply but I'd still check and double check the s video connection in the TX and double check the solder joints - after that it's in Sanders court!

[j5coat]

hes a great dog! I have double checked the connections to the tx via the 9303 and everything is good there, i am using the stock connector that was used to connect the 72mhz module to the radio and it has a nice tight fit. i have also tried powering it with a fully charges 3s 460mah lipo with the same results, ruling out a lack of power from the tx, and even if the 9303 was not powered the lipo will turn on the ezuhf when its cooled down. im stumped.

[ssassen]

There's normally nothing that can overheat in the EzUHF Tx as the power dissipated in the RF output stage is a mere few hundred mW (milli Watt). However for the sake of argument lets say it is overheating and shuts down this can only be caused by one of the voltage regulators having to dissipate too much power. Are you 100% sure you hooked it up correctly? Can you show me the pinout of the transmitter and how you've hooked it up as I'm not familiar with that particular radio?

[ssassen]

Just watched your video, to me it seems it is going into low voltage cut out mode. I also only hear two beeps during powerup, indicating it is running off of 2S? I need a little more info on what you've got running here. Is that a 2S radio? In which case I would suggest powering it from an external 3S battery using the Tx power connector (2.1mm barrel, center positive) on top as it needs >8V to deliver specified performance.

[j5coat]

The radio is being powered by a 9.6v battery and in the video the voltage is 10.3. I also tried plugging in a 3s lipo but it had the same result. The 2 beeps you hear are from my jr radio, you can hear the difference at 2:00 and again at 11:20, the ezuhf tx is turning on with the radio, outside ( 9:30 ) just the radio powers up. i was able to replicate this every time it was used outside, and when i was out flying it was powered by a 3s lipo, so i am pretty sure it was the ezuhf module. thanks for the reply ssassen.

[ssassen]

Can you show me the pinout of the transmitter and how you've hooked the EzUHF Tx up as I'm not familiar with that particular radio?

[j5coat]

This is how the pinouts are on the radio. Everything is connected to the correct pins according to the ezuhf manual. i have triple checked all of the connections. It actually has not shut down, only failed to turn back on when the power is cycled.

[ssassen]

You only hooked up PPM, +BATT and GND right? Does the EzUHF Tx beep when you power up the radio?