Swapped a microcell and only power light comes on

@NoSignal - you need to replace the ac adapter with a new one that is rated for 12VDC and is outputting 12VDC minimum with load. Otherwise you will develop the same problem again. The minimum output is 12VDC with load. If you're only measuring 10.3VDC with no load, who knows what the actual output is once you start drawing current. Replace the adapter with a new one.

@NoSignal - by "swapped" MicroCell, so you mean that AT&T replaced your old one? If AT&T did, did they send you a new ac adapter with it as well, or are you using the original ac adapter that is 7 years old? If so, I would check the adapter with a voltmeter to see if it reads 16VDC +/- 0.5 with no load. We have seen countless times that when the adapters start to fail, all kinds of odd problems occur. It could be delivering just enough power to detect, hence the solid green power light but not enough power for the radios. If that's the case, replace the adapter with one of the same power rating, check it, and put it into use to see if that corrects the issue.

If you are using your original Mcell's AC adapter with the new 154 Mcell, then I would say that the adapter has failed.  You can check the adapter by measuring the output voltage with a voltmeter.  It should read 16 VDC +/- 0.5 VDC.  If it doesn't, then you've verified that the adapter has failed.  Replace the adapter with a new one with the same output specs as the original adapter.

I'd still check the adapter output voltage even if you received a new adapter with the 154 Mcell and are now using it.  It could be bad also.  We've seen a lot of these failing recently.

If your voltage measurements show no issues with either adapter, then I would suspect that the replacement Mcell is bad.  This is assuming that you've connected the Mcell properly and haven't changed router settings.

@NoSignal - we are assuming it was the ac adapter? What did it read?