Based on testing against other mosaic-x5, I thought that I was running into thermal issues based on the deployment that I chose … high device temps due to lack of airflow ultimately causing the device to lose reception from ALL satellites.
My issue may still be thermal, but not because of the enclosure. I replaced the device with another, then tested side-by-side today. New device in the enclosure, old device not, both powered by the same USB-C source, antenna placement about 12" apart with a clear view, same same as much as possible, with the difference of the enclosure itself. New device locked in an enclosure with convection airflow, old device free-air.
I even updated firmware to latest (4.14.4) on both to make sure that behavior didn’t change.
After 20h of runtime, device A (new) is rock solid and reporting temps of 56C. After leaving device B (old) alone today, the device is now reporting temps of 71C and has lost all satellites. I’ve rotated nearly everything in the solution, cables, antenna, power, location, you name it during testing.
Before requesting a RMA, are there any troubleshooting steps that would be beneficial? Adding airflow? Freeze spray? Seance (I have an old priest and young priest on speed dial)?
I would go ahead and presume that with time & cycling the 2nd unit will develop heat issues too (best to proceed with caution foremost); try adding a fan/cooling to the overheating unit to see if that helps (and probably also to the new unit) - any temp change?
Thanks Russell … so far unit 2 is behaving itself, while the original is … cooking itself by 15C on a regular basis now. tl;dr I’ll likely need to request an RA for this unit for review and replacement.
I have a handful of muffin fans to vent as you’ve recommended, however am concerned based on the design of the unit itself as it relates to airflow. The X5 RTK eval kit is sealed, does not connect anything to the Alum heat sink (AKA, the case), and the case itself does not present a notably heated surface.
You likely see where I’m going.
I’ll strip the device and actively cool hotspots as I can see with thermal camera to see if there’s an obvious answer … however thoughts from what your design team has in-depth insight appreciated.
Hi Russell – I submitted an RA a bit ago for a device swap, however haven’t heard anything back. Not sure if it’s because of a hyper-active SPAM filter, but can I ask for a huge favor and a nudge to the right folk?
I originally thought that this was a thermal issue, but noticed that my symptoms (now) are closer to what’s described in RTK Mosaic-X5 Issues – I need to grab and attach a scope to troubleshoot prior to sending off, but am curious if I should look at similar conditions to address long-term. Key to note … I’m in So Cal, so we have no weather … let alone lightning.
Many thanks for the extra info and detective work. It does indeed sound like you’re having the same issue as our other customer…
Please get the unit back to us. We’ll test it, swap the diode out, retest (!) and get it back to you.
The diode is the PESD0402-140 from Littelfuse. 0402 is the package size (yeah, sorry, I need magnifiers too!). 140 is the operating voltage: 14V (14 * 10^0). It is the right part for the job. In your case, maybe ESD has caused it to fail? But I’m guessing. Please get it back to us and we’ll take it from there.
Thanks for your support - and apologies for the inconvenience,
Paul
Appreciated Paul, and thanks for the confirmation. I found the P/N from the PCB assets, and was glad I guessed right to confirm specs …
Based on failure pattern I’d be surprised if it was ESD, but stranger things have happened. Hopefully that’s all it is and it’s a simple fix.
Currently working with John on the RMA, appreciate everyone’s help with this.