Pixhawk led flashing yellow, no arm, no message in hud

Thanks in advance for any help. Pixhawk PX4, Arducopter 345 helicopter, 500 helicopter. Problem is Pixhawk is double flashing yellow led (error code will not arm) there is no error message in Mission Planner hud screen, in failsafe screen Stablize is showing in red color, radio and accel and compass are calibrated. Preflight checks disabled in full parameter list. Any process to find what is causing no arm and yellow led?

Good day, yellow led mean low battery, did you check the correct calibration of your power module?

Thanks Sir but power module is not the problem, 5.3volts output

Hi William,
Good to see you on the forum again.

Any reason why you are using such an outdated version. 3.4.5 is missing a lot of important changes that Chris and I made to get the code working well again. If you don’t want to upgrade to 4.0.5 then at least upgrade to 3.6.12.

Is the controller a pixhawk 4?

Are you saying that ARMING_CHECKS is disabled? If so then enable arming checks and it should tell you why you are seeing a blinking yellow light. Go to the flight data screen of mission planner and under the HUD there is a bunch of tabs. Choose the messages tab. It should list out the pre-arm check failures. If you don’t know how to fix them then post what they are and we can probably help you.

Updating was not a good idea this time. I updated to Copter heli 4.0.5 in mission planner, problem is now I cannot connect via mavlink, showing no comport detected. When I go to Windows device manager ports all it shows is FMUV2?
Any ideas how to fix this problem?

So you are trying to connect via USB directly connected to the flight controller? Are you using the latest version of mission planner?

Thanks Bill, Yes directly from Pixhawk to usb port, but my Mission Planner is about a year 1/2 old, I will update and try.
Is it better at this stage of the game to use Mission Planner or Qgroundcontrol for a helicopter?

Yes mission planner or QGC. We have designed the heli page to be the same for arducopter versions 4.0 and beyond.

As for the selection of COM ports in mission planner, I think the USB connection no longer comes up as a COM port but FMU… and might even have “(mavlink)” after it.

Thanks again all, I updater both QGC and Mission Planner and was able to connect, I will enable arming checks in MP and maybe I can see what the problem is

Do you have arming switch ?

No arming button, disabled in full parameter list

Just calibrate your battery monitor… maybe the configuration of your power module its incorrect… check also if you have set correctly your failsafe value in MP failsafe

Hi i have the same issues with my ardupilot where the motor is not arming after i have armed it with the radio transmitter and receiver, also the ardupilot keeps flashing yellow lights what might be the issue

Hello, how did you set your radio failsafe?