Figured out this problem, when I installed the extended GPS mount it came with two cables on a 5 pins and the other with 6, I had the 5 pin cable installed and based on what I read in another thread here I swapped cables and now no problem starting up with the GPS…
Next issue is the Pixhawk with the SimonK flashed ESC’s, looks like I am experiencing the sync issue I have read about in other posts…
I am having a similar issue as piersc.
I just bought a pixhawk from Canadadrones.com. Received it earlier in the week and had the pixhawk all working on the bench. The 3DR power module (5.24V) was providing power to the unit with X8R via SBus plugged into RC port. I also had a Turnigy plush 60A ESC that was outputting 5.2V on Ch.3 on the board, RFD900 on the Telem 1 port, 3dr gps/compass, and 4 servos plugged into 1, 2 4, 7. Everything working like a charm. Next thing I know my transmitter started beeping like it lost the RX. I noticed the power led disappeared from the RX and MissionPlanner reported loss of signal. I repowered the pixhawk I could not get anything working again and I had the same tones and leds as piersc, except for the IO B/C led was solid red and the IO ACT is solid blue. I too inspected the log file on the SD card and it stated ‘PX4IO board not found’. I measured the voltage coming out of the RC port on the Pix hawk and it is only showing 3.4V. After I had a small panic attack and came back to do some further troubleshooting, I measured the voltage again and it was now only 2.0V out of the RC port? the Pixhawk also seems to have a slight burnt electrical smell to it. gulp!
What has happened? What should my next steps be…except away from the window. Your help is greatly appreciated.
I bought my pixhawk a week ago from readymade and have the same problem! Anyone got any solutions?
So what is the answer to this problem? Ask for a RMA?
I likewise have a pixhawk that fails to start. I tried all of the above methods, none worked. I did a full start up diagnosis and have determined that my ms5611 is failing to start. Also, the mpu6000 starts fine, but sometimes other tests say that it fails. Here is the bootlog,
[size=85]Running rc.APM
binfs already mounted
nsh: rm: unlink failed: No such file or directory
Detected FMUv2 board
[uorb] already loaded
uorb started OK
px4io: already loaded
PX4IO board OK
CRCs match
PX4IO CRC OK
Setting FMU mode_pwm
<fmuservo> MODE_6PWM
<fmuservo> set_pwm_rate 0 50 50
Starting APM sensors
[MS5611_SPI] on SPI bus 1 at 3
<MS5611_SPI> crc failed
<MS5611_SPI> prom readout failed
ms5611: interface init failed[/size]
Having used Mission Planner, APM Planner 2.0 and QGround Control to try and shake things loose, I decided to erase the flash and load a new boot loader version (4) onto the pixhawk, then load firmware for the FMU and IO board using Mission Planner (it seemed most reliable). Having done this, it reports that I am up to date and it still fails to initialize. I contacted 3DR and asked for help, they offered me a discount on a new unit and told me that could not repair the one that I have. Does anyone know a good place to source the ms5611? I’m going to try and repair it myself.