Jaguar Failures

[duane]

We have managed to have 4 Jaguars that have failed. This is quite unusual for us. We have used Jaguars since the first year they were available (5 years?). This is the first time we have had this many failures.

The failure mode is that the Jaguar goes dark, no lights. When I hook the Jaguar to a variable power supply, the supply is unable to provide current to the Jaguar, indicating a short on the power supply side.

Inspection doesn't show any obvious signs of failed components.

I believe the failed devices are models from previous years before the conformal coating change. Debris is a distinct possibility, but I would hope that the device would recover once the debris is removed.

I'm looking for suggestions for diagnosing the problem, preventing additional failures, and potentially recovering these devices.

Thank you for you suggestions.

[Ether]

I believe the failed devices are from years previous to the conformal coating change...


Just to be clear: these particular Jags were working this season, and then they failed?

[duane]

Just to be clear: these particular Jags were working this season, and then they failed?




Yes. The Jaguars have been working for quite a while. Then they failed.

Thank you for asking.

[Ether]

Yes. The Jaguars have been working for quite a while. Then they failed.

Thank you for asking.

Even though these are older Jags, I suggest that you contact VEX support and let them know what happened. It's possible they may ask you to send the Jags to them for failure analysis.

[Dale]

We've seen lots of problems with older firmware a Jags not putting up with rapid reversals of direction due, I assume to back EMF and huge current spikes. A year or two ago TI (pre VexPro) did a firmware update that included some fast automatic ramping. We had given up on Jaguars by then so I'm not sure if that fixed it. We always ramp our speed controllers in software now to avoid huge current spikes.