blinking network light

@egpolsky - which MicroCell, white or black model?

The flashing green 3G light could be indicative of a couple of different issues (see my QuickTips Guide, link is in my sig line as well as links to my Tech Guide and Cellular Booster Guide). Most of the time the reason is that the MicroCell has lost connectivity to the AT&T Mobility Servers which can be the result of a failing MicroCell, failing ac adapter, or quite often something has changed with your ISP. Charter (Spectrum) has had lots of issues in the past with losing the MicroCell's connection to AT&T, mostly due to a pushed upgrade to the Arris gateways which changes or alters a setting somewhere. You will have to work with Arris and/or Spectrum on how to check your router settings because that is beyond what we, and AT&T can do here. There could also be line quality issues (which is not uncommon for Spectrum). You can check your line quality at voiptest.8x8.com to see if there is excessive jitter, lag, etc that is interfering with the secure 24x7 VPN connection that the MicroCell requires.

Don't expect Spectrum to help you with the MicroCell because the can't, or won't. AT&T support is pretty much useless now because all they can do is follow the script which rarely corrects issues. Sales of the MicroCell were discontinued at the end of 2017. AT&T will still continue to offer some sort of support but the service will eventually be discontinued as well sometime in the future. What AT&T, and us recommend now is WiFi-C (WiFi Calling) if your phone is capable of that.

WiFi-C works very well for most people and is really only subject to the quality of your WiFi and the other issues that affect WiFi in general. However, you should not attempt to use WiFi-C within range of the MicroCell that it is registered to because the phone will not know which connection to use and the result will be a poor connection in general. The phone can not automatically choose which connection to use, your WiFi or the MicroCell's 3G signal, which your phone is specifically registered to. Either disable the MicroCell (power off) or place your phone in Airplane Mode to turn off its cellular radio so that it can't connect to the MicroCell's cellular (3G) signal. I've been using WiFI-C exclusively since early January and have no issues at all, either at home or when I'm out and about. Handing off, in general, from  a WiFi-C connection to a cellular connection is not as smooth as it should be because of the technologies involved. Some of that is covered in my Tech Guide. Basically, if you start a conversation on WiFi-C, and then move to an area where the cellular coverage is better, your call will be dropped, and vice versa. Handing off between the two technologies is not a linear process. For me, I just leave WiFi-C enabled all of the time and forget about it. If I'm at a friend's house who has poor AT&T coverage, I just log in to their WiFi network (with permission of course) and calls work perfectly. The next time I'm at their house, my phone logs in automatically so I never have to mess with it or worry about missing a call.

The only other options that will be available to you once the service is terminated, besides WiFi-C, is to purchase a cellular booster (see link in my sig line), switch carriers, or possibly try Google Voice.

So I ordered a new power cable from amazon and it solved the problem. Wish att would have suggested that as solution during my 40 min troubleshoot phone call w them. Thx for your help

@egpolsky - that's why I wrote the Tech Guide. AT&T Support doesn't have the support that they need and is not allowed to reference my Tech Guide because it is not an "official" AT&T document.

I would strongly suggest that you switch to WiFi-C (WiFi Calling) if your phone is capable. Sales of the MicroCell were discontinued (as of the end of 2017) which means that the service itself will eventually be discontinued as well. If WiFi-C is not an option then your only other options are a cellular booster (see link in my sig line), switch carriers, or possible try Google Voice.

@egpolsky - handing off a call from WiFi-C to cellular is not seamless for reasons given in my Tech Guide in the section about handing off (see link in my sig line). I have no issues sending an SMS from my iPhone 8 Plus to an Android phone when WiFi-C is enable.  It's slow but it does work. I just leave WiFi-C enabled all of the time and don't think about it. It's great when we're at our friend's house, and vice versa, because both of us have poor in-home AT&T coverage so WiFi-C works perfectly for us.