Vex Cortex port10 not working...

Today our team found that port10 on our cortex was not working. We only have a week until a major event and we can’t think of any way to fix it.
Would there be a way we could use a power expander / more y-cables?

We have already used two Y-Cables on our robot, and no ports are left.
Our robot requires 12 motors, but as previously mentioned only 1 doesn’t work. Port10,
we have swapped things and tested a variety of things and can confirm the problem is coming from the Cortex.

Does anybody have a quick fix that we can do within half a week?

Port 10 not working means you have blown the internal h-bridge. If you have someone that is good at surface mount repair you could replace the two ICs inside however that would make the Cortex illegal for competition. You can use more than 2 y-cables as R12 does not have a limit just a max of 1 per port

Just use a different cortex

Relying on ports 1 and/or 10 for competition is generally not a good idea. They are very prone to premature failure and might well fail during competition when you don’t have time to rewire.

As something of an alternative, you can legally use up to 3 Y-cables with a single Cortex port if 1 Y-cable goes from the Cortex to 2 Power Expander inputs and the other Y-cables go from the corresponding Power Expander outputs to Motor Controllers. I’ll find the Q&A ruling for this if you’d like.

@Barin thanks that would be nice :smiley:

It turns out that the Q&A ruling I had in mind was from Starstruck rather than In the Zone, but, as the rules concerning the matter haven’t changed, most inspectors would probably maintain that the ruling is still valid.

Nevertheless, you may want to ask again in this year’s official Q&A just to be extra sure.


@SpencerVaughan Seeing your Q&A, the rules confirm that there is no “maximum amount” of Y-cables. What I meant was that it might be worth confirming the legality of using Y-cables from power expander outputs whose inputs are connected to the Cortex via Y-cables.