@Virgo ,

Thanks for your quick response.  The article was very helpful and I believe it answers my question if either of the following cases is true:

Case 1

• My POE switch only supports Alternative A (power on lines 1, 2, 3, 6)
• The EAP225 only supports Alternative B (power on lines 4, 5, 7, 8)

The specs on TP-Link's site for the EAP225 state:

• 802.3af/at PoE
• 24V Passive PoE (+4,5pins; -7,8pins. PoE Adapter Included)

From this I see that the EAP225 accepts power on the Alternative B.  The article states that the 802.3af/at protocol for PD's (Powered Devices like the AP) is that they should accept both Alternative A and B while the PSE (Power Source Equipment like the POE switch) can use either one.  Given the fact that the EAP225 did not light up when connected to my POE switch would suggest that my POE switch is not sending power to the Alternative B lines so it must be sending it to the Alternative A lines.  If this is true, then since the EAP225 did not power on when connected to the POE switch, it does not accept power on the Alternative A lines therefore it only accepts power on Alternative B.  Further, this would mean that the EAP225 is not following the 802.3af/at protocol since it does not accept both Alternative A and B.

Case 2

• The EAP225 reverses the polarity of line pairs 1,2 and 3,6

If this is the case, then the article suggests using a crossover cable for those pairs when connecting with the POE switch.  I assume for this to work that both the power AND data signals must be reversed in the EAP225.  Do you (or anyone else) know whether this is true for the EAP225?  I would hate to blow up my EAP225 testing it with a crossover cable if this is not true.

Thanks!