Nova Cat-M1 & NB-IoT does not power up (no LEDs)


#1

I just received a new Nova Cat-M1 & NB-IoT and followed the instructions of activating SIM, installing SIM, connecting antenna and then connecting USB to host. I never get any LEDs on the USB device. My host is a beaglebone black being powered with a 2.5A power supply.


#2

Does it work on a desktop / laptop? Try it on a “proper” PC first and debug any issues there. It will help to isolate if its a Nova issue or a Nova<->beaglebone issue.


#3

No, plugging into my Dell XPS 15, still no LEDs.


#4

Hmm, only thing I see is it could take up to 30s for the power light to turn on once plugged in. If it doesn’t turn on in 30s+ and you have a multimeter you could try probing between TP32 (GND) and TP31 (USB_5V) to make sure 5V is present, and TP32 to TP30 (+3.8V) to make sure the onboard step down converter is working.

It definitely should work fine or your laptop. Last thing I could think of would be to remove the simcard and maybe the antenna just in case one is causing a massive short on the board (the device should power up fine without either but obviously wont connect to the network).

The schematic and PCB Layout is available: https://github.com/hologram-io/nova-hardware/blob/master/Hologram_Nova_Schematic_J.pdf


#5

Am I missing some capacitors? Or does this model not use them? I don’t have C47, C49, C50.

I probed those test points and I am getting no VDC at any test points.


#6

Yeah those aren’t populated on the Cat-M Nova


#7

If the power LED is definitely not coming on then you might have a defective model. Can you reach out to support@hologram.io and we can get an RMA going? It would be good to get that back so we can see what went wrong. Every board is powered up at the factory so it’s odd that this would happen.


#8

I purchased the device from digikey and have started a return with them. I assume that is the route I need to take? Or should I still reach out to support@hologram.io?


#9

Did some more troubleshooting and the issue appears to be internal between the USB Vcc connection and L1.


#10

It’s weird, when I take VDC measurements with the device plugged in, I get 0VDC at L1. Unplugging the device and measuring continuity between the Vcc leg of the USB plug and L1, I get 0 ohms. If I take a jumper wire and jump Vcc from the USB to L1, the power LED illuminates blue after approximately 5 seconds.


#11

Sorry to be “spamming” this thread but the issue was a bad solder joint at the USB Vcc leg. I re-flowed that joint and now get the power LED when plugging in. Hopefully the rest of the circuit is sound as I likely just voided my ability to return it. (Sometimes I hate being impatient :slight_smile:


#12

Nice debugging job there. Glad you got that fixed. We’ll let the factory know to keep an eye out for this problem on our next production run.