Pneumatic Control Module Power Issue

[KettleFallsTeam]

Earlier in the 2015 build season we were working with the pneumatic control module to run the compressor and a couple of solenoids. Everything worked fine at the time, however we did not need it on the robot at the time so we took it off. Now we are trying to use the pneumatic control module once again, but we cannot get the control module to work. It acts as though there is no power going into the device. We checked the voltage on the wires that we have going into the device and it is a strong 12 volts. Yet, when its plugged in we do not have any status lights show up, and we cannot run the compressor, or any solenoids off of it.

[xXhunter47Xx]

Quick question for my own sanity, are connected to the can bus? You haven't mentioned checking that so I just want to make sure.

[KettleFallsTeam]

We are connected to the can bus. However, we cannot get a reading from it since the whole pneumatic control module is not getting power.

[Jared]

We experienced a similar failure with ours. We can measure 12 volts on the traces of the board, but there are no status lights. Some tiny surface mount part on the board appears to have failed.

[KettleFallsTeam]

That's what we are experiencing. We can measure 12 volts on it, but we have no status lights on it. Have you found a fix for it? We are dreading buying a new one because its a 90 dollar part, and it is costing us 70 dollars to ship..

[Jared]

That's what we are experiencing. We can measure 12 volts on it, but we have no status lights on it. Have you found a fix for it? We are dreading buying a new one because its a 90 dollar part, and it is costing us 70 dollars to ship..

We couldn't identify the broken part, so we weren't able to attempt a fix. Our team decided not to use pneumatics and not to pursue a solution to this problem.

I'd get in touch with CTRE and send them an email.

[cgmv123]

and it is costing us 70 dollars to ship..

Shipping for just a PCM should not be that much. Overnight to Wisconsin from AndyMark (in Indiana) is $38.98 for the PCM; Next Day Air to Wisconsin from Vex (in Texas) is $27.99 for the PCM. That's if you need the PCM within a day or two. Ground shipping to Wisconsin from AndyMark (in Indiana) is $8.97 for the PCM; Ground shipping to Wisconsin from Vex (in Texas) is $5.74 for the PCM.

(AndyMark is about 3 times closer to Wisconsin than Vex, and their shipping is somehow more expensive. :confused:)

[Ether]

Some tiny surface mount part on the board appears to have failed.

Did you take pictures?

[KettleFallsTeam]

We may have found a potential fix; we have discovered that our 20 amp fuse on the power distribution board may be burnt out

[Ether]

We checked the voltage on the wires that we have going into the device and it is a strong 12 volts.

we have discovered that our 20 amp fuse on the power distribution board may be burnt out

Hmm.

[billbo911]

We may have found a potential fix; we have discovered that our 20 amp fuse on the power distribution board may be burnt out

So you can measure +12vdc on the board with a open fuse feeding it?
Separate but related question: Are there fuse monitoring circuits on the new PDB as there were on the old one? If so, is that is what is feeding the voltage to the PCM board, but not enough current to boot it?

[Mark McLeod]

Separate but related question: Are there fuse monitoring circuits on the new PDB as there were on the old one? If so, is that is what is feeding the voltage to the PCM board, but not enough current to boot it?
No.
No LEDs light up when a breaker is missing, but wires are attached like the 2014 PDB.
The 20a fuse is for all current headed the PCM's way.

[billbo911]

No.
No LEDs light up when a breaker is missing, but wires are attached like the 2014 PDB.
The 20a fuse is for all current headed the PCM's way.

Right, dedicated power for the PCM, forgot about that.

Now I'm even more confused. How could they have measured 12 volts on the PCM board, yet had an open fuse feeding it?
There must be some new magic in the control system for 2015.

[Mr V]

Right, dedicated power for the PCM, forgot about that.

Now I'm even more confused. How could they have measured 12 volts on the PCM board, yet had an open fuse feeding it?
There must be some new magic in the control system for 2015.

Well it is unlikely for the standard automotive fuse to fail in this manner but if a tiny portion of it is still connected it will flow enough current for a volt meter with a 10megaohm input impeadance to show "12v". However it won't flow enough current to power up the board. This can also happen with really bad connections. For this reason a volt meter is a poor tool to check for power on a load level circuit. You need something that will put some load on the circuit like a test light.

[KettleFallsTeam]

Well, we replaced the fuse and we are getting the same results. However, after listening to the discussion here, we must have burned out the fuse while playing with things after it was already not working. We have checked some of the parts on the board. The little fuse on the PCM is still good. Voltage is going in to the pins on the board. Unfortunately, the overnight shipping to Washington state is $70 but, I'm thinking we will just do the advantage shipping as saving one day doesn't justify the $70. If only they could fulfill the order faster than three days.

Thanks for the all the help, we have an electrical engineer poking around the board right now as I type so, I will keep people posted on what may have happened.

Cheers!
Canine Crusaders #4980

[nedwards28]

Well, I said I would update, so here I am. I think while younger teammates were working in the control system wires were pulled or inserted when it was on. Taking a look at the PCM, we couldn't see any processing going on or any indication that it was working beyond power in.

We contacted Cross the Road and they replaced the module for us. They were exceptionally helpful and easy to work with with.

Thanks everyone! Good luck in the last few hours!