Sounds like your computer might benefit from a good old fashion reinstall of windows to clean off all that legacy drivers and such. Windows is a finicky thing and not always predictable.

DJ,

Thanks for your response, but the EZB drops off the list of available wifi connections regardless if it hook to anything. That was the test I did when I just hooked it up to a power supply (many different ones to see if that could be it)with no PCs running ..etc and just periodically looked to see what was available ( home wifi, EzB, next door wifi..etc) and the EZB vanishes after ten or so min as described above.

Yeah - that's why i mentioned windows may need a refresh if it's not seeing all of the wifi networks. There's never been an instance of an ezb having wifi broadcast issues in the hundred thousand units.

Unless for what ever reason it is browning out. But you've covered everything by stating the power supply was changed and such. If the blue light is flashing, the good ol' wifi is broadcasting.

Ahh ok. I will give that a try. Curious why would it also disappear off my on my iPhones list of available networks as well?

Well, that throws a wrench in there. If it's disappearing off other devices, then something is up. Something that I have no experience with, unfortunately. And wouldn't know where to start... I would have mentioned power related, but that's covered, as you said - and you're an experienced dude. So it's really tough to say. Unless over the years a solder joint somewhere on the pcb has wore loose? Or some physical connectivity issue that's providing unpredictable results. Since it's never happened before, it's an anomaly. I'd suggest replacing the top pcb with a new wifi from EZ-Robot, but i can't be certain it's wifi related. It may be power supply related on the bottom board. It's really impossible for me to be certain

Oh - maybe try changing the wifi channel on the ezb's? Perhaps lots of congestion in your area on the current channels. The wifi channels of the ezbs should be on different channels as well.

I'm stumped because it's happening on two ezbs and you say it's reproducible with other wifi clients (such as an iphone).

Thanks DJ  I figured it was something x-files like lol! I thought I would just give it a try to see if it has ever come up. I will report back if I ever figure out what's going on

Do you have a lot of metal or shielding surrounding your ezbs?