Just found out the hard way there is a 3rd way of powering pixhawk 5V servobus.
After changing all ESCs to make the Heavy upgrade work, the camtilt was dead.
Finding this thread I had a look and found that one of the old original BR ESC powered the bus!
One of the ESC had 3 wires to deliver 5V to bus…
Making a servobus connector from old ESC and some soldering solved that
I previously had issues with tilt and plugged a 5V into RC by mistake instead of SB and it blew the Pixhawk. I replaced the Pixhawk and simply ran to the Aux 5 to power the Bus with a parallel 5V wire which worked fine. I recently blew that UBEC to Bus and hence tilt issue again. I saw this thread which confirmed I should power through the SB port which I plugged into with a new old style UBEC but upon powering up I didn’t get light and found UBEC to not work. So I now installed a new style regulator and verified both legs getting 5V. Plugged into SB and Pi board and powered up and I got nothing. Checked regulator and it’s now blown too.
I plugged old style UBEC into Pi Computer and now am back to square one. Everything comes on but no tilt until I can parallel some power to bus.
Don’t understand why SB port is blowing UBEC’s? Any ideas?
This post is helpful. I just upgraded two ROV2’s to the heavy configuration. One had two of the 5V regulators and this upgraded fine. However, as mentioned by @Boko, there is a version with older ESC’s that power the bus directly and those ROV2s only have one 5V Regulator so when upgrading to the heavy configuration you lose power to the bar and need to run another regulated RV to the SB (Sbus) pins.