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RV12iS Lane A / Lane B /Fuel pumps fault before start

Bogdan

Member
I'm the owner of a new built RV12iS, with Garmin G3X. First engine start was performed few months ago with no issues. Previous to that, it was an issue with a faulty Arduino in the power module preventing the trim switches to operate. The Arduino was reprogrammed by a very experienced engineer here in the UK ( see the thread posted by him on this matter) and everything was fine. The avionics were checked many times since, with no issues.
Recently I noticed that the EFIS backup battery switch doesn't provide any power like it should be for the avionics when not Master switch dependent. I believed it's a battery issue so I was planning to replace the backup battery.
In the mean time, I installed the PilotAware with power taken from ELT ( which I did not installed). Checked, all good.
But then, few days ago, when trying to check the avionics and Lanes again, just to see if everything it's good, I noticed this:
- master switch ON, followed by Lane A and Lane B switches ON - those lanes are both dead. EFIS comes alive but the lanes not, fuel pumps not. Everything sounds literally like the battery is drained but the voltage measured at the battery is 13.6V.
If I switch the EMS backup ON, everything works perfect, Lanes ON, fuel pumps working, engine data showing .
The Rotax fuse box green leds are very faded, after few minutes they are completely gone, no illumination.
I red the most recent post with the approximately the same issue and I followed the steps recommended there, but no positive result. Attached it's a pic with the checks I performed.
HIC module light shows yellow. On the green HIC connector, if I put together pins 7+8 (K7023 and K7022) everything works normal.
I checked all the connections, all the pins, hopefully I didn't miss anything, all good.
Is this indicating actually an issue with AV60007 ignition module or I should consider something else. I am getting frustrated by this ongoing electrical issues as I had a few.
What is quite obvious is this: when switching the Master Switch on, everything looks and hears soooo slow ( like the battery is about to die - but the measured voltage is normal) . Once the EMS on, everything comes to normal. Backup battery is dead.
One other thing to mention is that on HIC module 8 pins connectors, the voltage between pin 5 and pin 7 is 13.19v like it should but between pin 6 and pin 8 is 0.002V.
Any advice would be greatly appreciated.
 

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Side note: while investigating this issue for Bogdan and examining the schematics of the modules (which Vans provides, to their credit) I noticed that just as on the AV-60000 module, Vans has omitted the input capacitor on the voltage regulator that powers the Arduino. On the AV-60000 they got away with this because the trim motor driver module mounted next to the Arduino includes a suitable capacitor. On the ignition module there is no other device to provide the capacitor. So there is a possibility that the regulator in the ignition module oscillates. When I find time, I will attach an oscilloscope to check.
 
Side note: while investigating this issue for Bogdan and examining the schematics of the modules (which Vans provides, to their credit) I noticed that just as on the AV-60000 module, Vans has omitted the input capacitor on the voltage regulator that powers the Arduino. On the AV-60000 they got away with this because the trim motor driver module mounted next to the Arduino includes a suitable capacitor. On the ignition module there is no other device to provide the capacitor. So there is a possibility that the regulator in the ignition module oscillates. When I find time, I will attach an oscilloscope to check.
I can confirm: the voltage regulator in my AV-60007 was oscillating. I will start a new thread about that.
 
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