There is no reason the cable connection would not work, unless there is something strange about the Philips design. Lyndel is correct it is a mono 3.5 mm (1/8") jack, tip being signal and sleeve being ground. Isolation through a xantech amplified connecting block should work but that would be an expensive solution. I do not have a Philips extender (I do have an Edge) or a would try adding a series resister in the line to limit the current draw 1/4 watt at 1k ohms to start and go down to lower ohm values until it works. Also adjust the power on the extender port.

Give DVDO a call and they will tell you where the IR receiver is. It is not shown in the manual I have, and I have no idea where it is as I use the rear port.

There is a PC program on my web site (www.the-gordons.net) that produces all of the edge IR patterns including the ones not on the remote in Pronto HEX format. The Edge is unique in that you can do everything (e.g. set brightness to 25) using IR. Just no feedback.