MSH Brain 2 HD not correctly initializing
I have a MSH Brain 2 HD unit that sometimes refuses to initialize, and emits 4 red flashes constantly. What does this mean? I usually disconnect and reconnect power and after some trials the unit finally initializes and I can fly, but I don't fly relaxed thinking that something can fail. Unit is upgraded with latest version.
Thanks for your support.
When the unit is powered up, a large number of tests are performed, among which the correct communication between the gyroscopes and the CPU.
If this specific test fails, the unit does not complete the initialization and therefore does not allow flying but generates 4 consecutive flashes of the red led.
Other types of tests can generate 5, 6, 7, 8, 9, etc. consecutive flashes of the red led.
The gyroscope test is a very strict test and it can happen one time out of a hundred that the gyroscope fails without real communication problems.
In these rare cases, it is sufficient to disconnect the control unit and power it up again.
Once the test is passed, the Flight Control Unit is working properly and cannot crash in flight under any circumstances.
If the 4 flashes are always repeated, this means that there is a serious fault in the gyroscopes.
If, however, as in your case, trying to power off and power on the control unit again, the control unit works, it means that when the test is performed, the supply voltage has not yet stabilized but continues to vary (increase).
This is a symptom of a poor and/or defective power supply.
If you are using a BEC, the BEC is delivering too little current and the filter capacitors are taking too long to charge and stabilize. Then when the capacitors are fully charged, removing and quickly reconnecting power will cause the voltage to rise faster because the capacitors no longer need to charge and do not draw current from the BEC.
If you are using a 2S lipo, it means that the lipo is half discharged or has a too low "C" value, or uses too thin cables or connectors with high contact resistance that allow too little current to flow.
Thank you very much BrainDev for your quick and very detailed answer, as always. I'm using a 2S lipo, so I will check the cables and connectors because they are very thin and they seem the root cause of my problem. I have the HD version, so I will extend the cables presoldered to the HD connector and then I will use it better than what I'm using now.