Blink-up to cellular modem not working

So…we’ve been using cellular modems for a couple years. However, we now seem to be having problems getting the imp002s to Blink-up. The device ID is: 20000c2a6906be80 and the firmware is 32.12. I’ve been away from the forums for a while, but I did not readily see a discussion about the topic. Also, I recently upgraded to an iPhone 6S (from a 5S) and don’t know if that could be a contributing factor. When I do a Blink-up, I get the long green LED, which I understand to mean it got the Blink-up information successfully.

The imp seems to be stuck in a long red followed by 3 short blinks – trying to get an IP address?

By the way, the device Blink(ed)-up successfully to the WiFi in the office. So, it seems to be an issue with the cellular modem.

Hmmmm…while typing this, I was interrupted and then restarted the imp002 and it’s now working. Any thoughts on what might be going on?

The imp002 I was working on dropped it’s connection (in the field) and would not connect, again. I tried another imp002 and it connected immediately and hasn’t missed a beat. I brought the original one back to my office and it Blinks up immediately to our office WiFi. I’m guessing there’s something different in how the cellular modem (Sierra Wireless) does its DHCP negotiation and the original board has become a bit “picky”. It has been in the field for something like 18 months.

We have DSL at home and sometimes CenturyLink (our ISP) does automatic firmware updates on our modem. Maybe after 18 months, a firmware update was made and some slight change knocked it out? It might be interesting to see if you could find out if any updates were made.

Couple of things:

  • Is blinkup working? (ie do you see solid green at the end of the blinkup). If you get that, then the phone is no longer involved with the process and can be ruled out. I only ask this as because you have to provide your own blinkup components on 002 etc there are ways to cause a failure here (not connecting VDDA to power, wrong bias resistor, phototransistor the wrong way round etc)

  • If blinkup is working, then try separating the hotspot from the imp. Some of them have issues with being too close to imps (and vice-versa - I’ve seen this with phone hotspots)

Long red+3 short is associating, not DHCP. It’s found the network but can’t join it. An incorrect password can cause that, along with any issues in the association process. See the note above about trying to separate the devices (ie, feet vs inches away).