Problems with PWM output on Pixhawk 1

Hello there,

I’m using the pixhawk 1 flight controller on a quadcopter setup. I managed to complete the whole setup process without any major problems in qgroundcontrol, but I do have a problem with the PWM output on the main outlets. When I go into the motor test section and try to spin up the motors individually each motor spins up for a short amount of time and then stops again. The slide bar is reset a short time after. I looked at the PWM output with an oscilloscope and indeed the signal changes for a short period of time after I set the slidebar up. After a short time it resets to the default value. Is this normal behaviour?

When I try to arm the quad the buzzer beeps and the status led is blinking red (I guess this means the arming was successful) but the motors do not spin up (I also don’t see a change of signal on the oscilloscope). However when the pixhawk is still connected to qgroundcontrol an error message pops up which sais that there is no CPU load information.

I recorded this log, where I gave input with my radio, as you can see on the manual input. The actuator shows the same output, but I could not see any PWM signal on my oscilloscope. In the example I didn’t connect the battery but even with the battery connected no motors are spinning.
Log 1

For the second log I recorded what happens when I give the input via the motor control section in qgroundcontrol. I activated each motor after each other as you can see on the actuator output section.
Log 2

Before setting up the pixhawk I had to put the firmware on the sd card because the pixhawk wasn’t connecting to my pc. But when it successfully connected I flashed the latest firmware again and continued with the setup process as usual.

Any help is appreciated,