3g light binking green or red....

A blinking green 3G means you have lost connectivity to the AT&T Mobility Servers. A blinking red 3G could mean you either have a hardware failure or you received an update and either the updated failed or the MicroCell failed to properly reboot and now it "thinks" there is a hardware failure.

Given that your MicroCell is a few years old I would check the ac adapter first. When they start to fail we see all kinds of odd things. Take a voltmeter check to see that the adapter is reading 16VDC with no load. If it isn't then replace the adapter with one of the exact same power rating because the MicroCell's are a bit finicky with their power requirements.

If the adapter checks out ok, then try a hard reset. Disable the power to the MicroCell (basically unplug it). Take a paperclip and press in the reset button which is located on the back. Keep holding in the button and restore power, and keep pressing for about 30 seconds. Release the button. The MicroCell will go thru the entire Initial Activation phase as if it was brand new, which will include any updates that may be available. You don't have to do anything with your myAT&T MicroCell account page.

The middle of the night is typically when AT&T will push any updates that are available and also do periodic maintenance to the MicroCell Service Area.

Thanks for the reply, Otto.

I measured the voltage of my MC power supply and it was 13 volts with no load.  While I understand that the voltage may be a little higher with no load than when under load, the label on my adapter says it's rated at 12v output (which sounds typical).   Thus 16 volts seems a little high to me.

But I would be willing to spring for a replacement if I can find an indentical adapater.

I will also try the hard reset.  Can't hurt and you never know.  I'll report back if the 3g light starts blinking again, before or after the two steps you suggested.

13 VDC output is too low for a no-load output from the AC adapter.  16 VDC is what has been typically measured from an operational Mcell adapter with no load even though it is rated at 12 VDC.  If your adapter is outputting 13 VDC with no load, then connecting the adapter to a resistive load (Mcell) will result in an output voltage lower than necessary for reliable operation of the Mcell.

Buy another AC adapter.  The specs are listed in Otto's Tech Guide at the link listed below.  Amazon sells Mcell adapters.  Make sure to match the output spec of the adapter to the particular model of the Mcell.

Oops, my bad! I meant 16VDC. Thanks for catching that. I really shouldn't type after two cups of coffee

@jefe

Avedis53 is correct. The 13VDC was a typo error on my part and fortunately he caught that. 16VDC is what we recommend. 13VDC is indicative of a failing adapter. Replace as suggested with a new one of the same rating and see if that corrects the issue. Sorry for the typo error.

Well, gents, I'm still skeptical that a 12 volt adapter needs to put out 16 volts under no load, but I went ahead an ordered a replacement from Amazon.

When the replacement gets here (about a week or so) I'll do two things.  First, I'll measure the no load voltage of the new adapter.  Then, before I install the new adapter, I'll find a way to measure the voltage of the old adapter when it's under load....that is, connected to the MC.  I'm expecting it will be ~12 volts under load, which is what is really needed.

I will report back. 

Thanks again for your replies.

I could go into the electrical theory about peak and root mean square voltage outputs from transformers but suffice to say that peak voltage runs 1.414 times (square root of 2) higher than RMS voltage.  If a transformer is rated at 12 VDC (RMS), then it's theoretical peak voltage should be about (1.414 x 12 VDC) or 16.97 VDC with no current load.  Accuracy is typically +/- 0.5 VDC for unregulated adapters, so we recommend that one should measure 16 VDC output as a rule of thumb for these adapters.

I understand your skepticism but I'm hopeful you'll see your Mcell running again with a new adapter.  As far as measuring the output of the old adapter under load, good luck with that.  That won't be easy but if you are successful, post your results.

Ok...the new power adapter for the MC has shipped.  I'll be reporting results soon.

In the meantime, I found 4 12 volt power adapters I have for other devices and I measured their outputs with no load.  They all were around 12.15 volts DC.

It seems to me that if a power supply has an output 25% higher than it's rated voltage when it's under no load, the capacity (amperage) of that device is too low.  It should be able to have close to rated voltage under no load and maintain that voltage under full load. 

BTW, the flashing 3g light hasn't happened again.  I hate intermittents.

If you were talking about higher-quality, regulated power supplies, I would agree with you.  However, the cheap wall worts are not designed to regulate output to that close of a tolerance.  You've got a little transformer to step down the AC voltage with a diode bridge to rectify the AC to DC and a couple of capacitors to smooth the power.  As the components age, especially the caps, these worts can go south as we've seen countless times.