I have an RTK Facet that will not power on. I have used a multimeter to check out the battery - seems like the battery is fine and charged. The behavior when plugging it in to charge seems to mirror this as the charging LED will only stay lit for a few seconds before turning off. On the main RTK Facet board the Stat LED will light up dim, then bright if you press the power setup button. The stat LED only stays lit for a few seconds. The screen doesn’t show anything. I also checked attaching a separate screen using Qwiic, but it doesn’t display anything. Connecting to a computer via USB-C doesn’t allow me to do anything with firmware, because the connection doesn’t stay open long enough. I’d like to get some help fixing or replacing the unit. This is the first time this one is being used. I have others that worked fine, so this is an issue I haven’t seen before
Try running through this flow chart
Here are the disassembly steps Disassembly / Repair - SparkFun RTK Product Manual
If those don’t get it going we’ll likely need it back for repair - click here to begin an RMA if so
AdamG,
Thanks for the very detailed report, your observations make troubleshooting much easier. Interesting that the display never turns on, but you are still able to see COM ports (even if momentarily). The display is controlled over I2C… I’m thinking that the I2C bus may be failing to initialize.
Since you mentioned having a Qwiic connector and a multimeter around, could you check the resistance across SCL and SDA on the I2C bus? An easy way to do that without opening the unit is to plug in the Qwiic, then measure across the two lines on the unconnected end. If you measure anything under, let’s lay 100k Ohms, there is likely a short on the I2C bus.
Sorry for the confusion. I never “see” the COM port appear. My machine will give me the sound for a connected device when I first plug it in, but I get the disconnect sound very shortly after.
Measuring between SCL and SDA, I get ~9.5 kOhms. If I attempt to power on the device the value changes to ~3.5 kOhms until I remove the multimeter and reconnect it to the same place. Then it goes back to 9.5 kOhms until I attempt to power it on again.
Following up, I can only see the COM ports if I hold down the power button, but even still they don’t stay open very long.
If it is the I2C problem as you suggest, how should I move forward? I now have a second unit failing for the same reason, which means I can no longer use RTK.
I currently have the first unit disassembled. Looks like all the connections are fine. The cables also look undamaged.
I am thinking I have done everything I can to assess/repair the situation with the tools and materials I have on hand. It’d be nice to move this process along…
I suspect this is a failing display. Please start a return for any affected units and we’ll check them out.
Hi Sparky - Thank you for your prompt response. I initiated the process earlier this week. I suppose I am being a bit impatient, but it is also slightly time sensitive. Thanks again.