Why do Access Points fail?

First thing to check is how clean and stable your power is. Power spikes are a leading cause of early failure of all electronic devices. In an apartment complex, beyond just a surge suppressor, I would want a full function AC line filter if not a line conditioning transformer.

Next, take a close look at where you are placing the devices. Are they exposed to excessive heat?
Are the antennas placed such that they would be susceptible to lightning? It does not take a direct strike to damage a transmitter or receiver. If the access points are up in or near the attics, both heat and lightning related surges could be the cause.

To offer further technical advice, I would need to know more about how the devices are failing.

You might want to pressure your dealer / distributor to arrange for a factory rep to stop in and look over your installation. They might see some issue that you are missing. Or suggest a different product better suited to how you are using the devices.

Chas

I would agree with Chas here and be looking at your mains supply as a first option.

If you need to restart these on a daily basis do they drop out at the same time? If they do that points to a possible Mains Surge/Spike or whatever. I had a similar thing with a Burglar Alarm at one place that I worked around 8.30 PM every Saturday Night it would go off and I as the Key Holder would have to drive in and reset the thing while the Police waited to make sure that there where no intruders. The unit had been fitted prior to an upgrade at a printing works about .5 of a mile away and whenever they turned on the printing presses that caused a drop in voltage and set off the Alarm.

A small UPS cured the problem and is something that I would try on some of the affected units 1 or 2 before getting to carried away with the problem.

Col

Thanks for all your help. I purchased another UPS today and plugged in one of the offending AP's. I'll see what happens from here.......

When you state that they have to be reset, that implies that they are locked up? That would point to either a firmware problem (bug) or power quality issues, as mentioned here. There could be network configuration/design issues or other faults that are creating extreme amounts of wired or wireless traffic and causing units to lockup.

I would also look closely at any temperature or humidity extremes that the units are subject to.

I have worked with Symbol, Cisco, and Proxim APs....Cisco is my favorite because the units are very rugged (rated for extreme high/low temperatures), perform well, and have an incredible feature set (for example you can do a full packet capture in a Cisco AP for troubleshooting)