Weird PDB failure - No LEDs

So we had a working robot at the end of build season, we had been driving and programming for over two weeks. Everything was fine. Robot went in the bag, and sat in the back of my classroom for 3 weeks. We get to the Pittsburgh Regional, unbag, power up, and the PDB shows no LEDS. The weird part was that it was till powering the motor controllers. Their lights were happily blinking away. According to documentation no LEDs imply reversed voltage to the PDB, (which it did not have) or no voltage (it had 12.4V). The CAN bus was fine, but it also didn’t show up in the browser where you check firmware.

We had to switch it out with one from the spare parts table at the regional, but now we are back home, and trying to figure out if we can fix this one, or what went wrong. Anyone have this before?

Haven’t seen that before, but it sounds like the “smart” circuitry in your PDP failed. This includes the CANbus, indicator lights, and current sensing. The rest of the PDP is just a normal high current fuse panel and distribution board so will continue to work regardless of the status of the rest of the electronics.

If you know you didn’t abuse it in any way, you just could have had a random early failure. Bad solder joints or a defect in a component worked long enough to get through quality control but failed after a short time in use at your end.

Will be interesting to hear from anybody else who had a PDP give up on them.

Have you checked the yellow (20A) and red (10A) fuses in the PDP?


We had a similar issue last year. One of our mentors made this thread:

You can see a few others had similar problems. I would contact Cross the Road Electronics and see if they can get you a replacement.

Open the case and inspect the circuitry that’s grouped around the CAN connectors for burned or otherwise damaged components.
We damaged one of these during the 2014 Beta testing.