So after having reconfigured my heli to use an external RPM sensor (see here: viewtopic.php?f=20&t=1580) and having tested it on the ground a number of times I went to the field today to try it out.

Unfortunately when I plugged in my flight packs the unit was completely dead. The unit was fully operational and ground tested the day before. Symptoms:
1. ESC was beeping with no signal
2. Unit light was off and did not pulse/flash as it usually does
3. Servo's not initialised
It did not initialise at all...

I thought it was a BEC failure so I disconnected all servos and the ESC and tried with a 2s life pack. Nothing, same as above. Then I plugged in the servos, and still nothing.

To ensure it was not the power supply I reconnected the receiver, that is monitoring BEC voltage through telemetry and noticed that the sat light was on, the telemetry link operational and reporting 7.6V for the BEC (and also the LiFe pack).

As a last ditch attempt, I tried connecting the unit and attempting the FW recovery procedure. It did not work either (unit off, plug in PC, open app, go in "no demo" mode, select flash F/W, when clicking ok plugged in power to the unit).

The unit was bought from the Spirit e-shop on the 29th July with invoice number IN16002037. Unfortunately I cannot get the serial number as the unit is unable to power on (and I think I've thrown the packaging away :S).

Can I send it in for inspection? Also any thoughts on what might have caused it? I can grab the Spirit off my 450L and put in the Goblin black thunder but am afraid it might cause that unit to fail too :S

The heli setup is as follows:
1. ESC: Hobbywing 130HV with BEC set at 7.6V. Both leads plugged in.
2. RPM sensor: Hobbywing HV RPM sensor
3. Servos: TGY 725MG, BK 7006
4. Receiver: AR7700 with 1 sat using SRXL connection to Spirit Pro
5. TM1000 telemetry unit. Connected to Flight Pack for voltage telemetry (its working, even with Spirit Pro not working), receiver frame losses/fade telemetry (0 fades with Spirit Pro out) and BEC telemetry. Also connected to the RPM sensor for RPM telemetry (also working on yesterday's bench test). I checked the telemetry logs and there was nothing recorded for the session, which is odd - I would have expected voltage to be logged as a minimum.

So I could not resist and transplanted the spirit pro from the 450L. Uploaded my backed up settings and the Heli is fully operational. Did a no blade spool up and it is working well.

I disconnected the hobby wing RPM sensor and reconnected the hobby wing esc rpm lead as I was getting noisy rpm signal from the separate sensor as well so just to eliminate some redundant wiring. Also disconnected rpm telemetry as the HW esc rpm out lead does not like being spliced and connected to the FBL and telemetry at the same time

Thoughts? I'm at a loss :S Let me know if I can run any tests on the failed unit or just send it in?

Hi,

it is very sad. Unfortunately it is hard to tell what happened.

The last thing you can verify is, if the status LED flashes for a very short time during power up? (just for few miliseconds).

If not, then please send the unit to us. We will examine it and fix the problem same day we will receive the pacakge.
The only thing that come to my mind is some discharge that went through the unit. But it is just guess. We will find the answer.

Where are you from?

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Spirit System developer

Hey Tomas, I'm in the UK. It does not flash at all even for a split second unfortunately.

Let me know how to send it back, I'm equally keen on understanding what happened to prevent it from re occurring, especially mid air! I was lucky as whatever happened happened while powering on on the bench

Im curious to understand as whatever it was could have caused damage to my receiver and/ or telemetry unit which would be "interesting" if they failed mid air

We will inspect it and find the answer.

From UK it can arrive in 2-4 days with conventional shipping - RoayalMail. So we can use this way.
It should cost approx. 3.7 GBP.

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Spirit System developer

Perfect thank you. I'll post it today.

Ok unit has been posted. I've sent you a PM with tracking details and my personal details Thank you!!

So Tomas has repaired the unit. It appears that the external hobbywing rpm sensor malfunctioned and sent high voltage in the PIT (rpm sensing) pin frying the processor. I have removed the external sensor from the Heli and will only use the internal sensor going forward.


Again thank you Tomas for the prompt response and repair!

You are welcome, it is our duty to help you.

P.S.: The unit was repaired by our worker, not me personally. It should work as a new one in each case

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Spirit System developer

In which case please pass on my thanks to your employee as well

Thank you both for the service and for helping me diagnose the problem so it does not occur again in the future!