No Status LED on Jaguar

[kjohnson]

I've searched around and found plenty of information about meanings for the status LEDs on Jaguars, but nothing about what could cause a Jaguar to display no LED.

Our situation:
Four individual CIMple Box gearboxes powered by one CIM each. One black Jaguar per CIM. We are using PWM instead of CAN and therefore have not attempted any firmware updates. Two of these Jaguars are KOP, the other two from AndyMark (all new in 2012).

Out of the box, all 4 Jaguars seemed to work. Our first real on the floor drive test was last night. We noticed with a tank drive program the two separate gearboxes running the left side were turning at slightly different speeds. Same with the right side. We chalked that up to brand new chain and gearboxes. After driving around a bit, going over the barrier and bridge a few times, we noticed all wheels were no longer being powered. Two Jaguars were still working properly, the other two are still receiving 12V but show no status LED. Even if PWM cables come loose and don't provide signal, the Jaguars should still show some sort of status LED.

What could cause a Jaguar to quit working and display no status LED after it was just properly running? Can anyone suggest what we could try to test these Jaguars further? I know Jaguars have a history of problems, should I just contact TI for an RMA?

[billbo911]

No status LED sounds like no power to the Jag.
Did you verify the +12 with a meter at the input terminals?

[kjohnson]

No status LED sounds like no power to the Jag.
Did you verify the +12 with a meter at the input terminals?

Yes, both Jaguars in question are still receiving 12V at the input terminals.

[Jon Stratis]

Is anything rattling around in the Jag? It's possible something broke loose. I know back in Breakaway there was a huge likelihood of breaking the fans on the Jags loose going over the bump (I know all of our Jags from that year have broken fans, although the Jags themselves still work). I would imagine similar shock forces with the bridge/barrier this year as well.

Have you tried opening the Jags and seeing if anything looks funny? It's just 4 screws, but be careful of the wires going to the fan... you don't want to pull the entire terminal off!

[Alchemy99]

I aswell have this same problem, no status LED.

i have the scematic and i have been trying to diagnose the problem to the component level. i still have no luck.

PS. the main reason for replying is so that i can get notified if any help comes around.

[kjohnson]

Is anything rattling around in the Jag? It's possible something broke loose.

We did test going over the barrier, so its quite possible something inside shook loose. This happened so late yesterday that they haven't been removed from the robot yet. I'll get one of the students to do so tonight so we can check them. Will opening the Jaguars void any warranty or will I still be able to get an RMA through TI?

I guess it may be time to switch to Victors...

[Al Skierkiewicz]

Opening the Jag may affect the warranty. Check with TI first. It sounds like one of the internal regulators may have taken a hike. If you are sure you are measuring 12 volts at the input terminals, that is about all it can be. I ask about both terminals because it is possible to measure to one terminal while connected to battery common on the PD and still read +12 volts while having an open wire and no power to the Jag.

[Alchemy99]

when i went into the jag, i had the voltage at the terminals, but not at the microcontroller, and i was reading 1.3vdc where i was supposed to be reading 5v

[Al Skierkiewicz]

when i went into the jag, i had the voltage at the terminals, but not at the microcontroller, and i was reading 1.3vdc where i was supposed to be reading 5v
Well either the five volt regulator died or there is a short on the 5 volt rail someplace. Without the 5 volts, the 3.3. volt regulator can't come up.

[kjohnson]

Update: I submitted an RMA request to TI yesterday. They replied that they received my response and would need to do further evaluation before deciding whether to process the replacement or not.

And no, when we took the broken Jaguars off the robot we didn't hear anything rattle inside the case.