I finally got the test set to work. It was on another dsl line. I plugged into the jack and tested without any problems. On my own home testing I was able to get it to work but had to jump through some hoops. At my house when I tried at the jack I could not get it to connect and test. If I connectected to the 66 block, while the Efficient 5100 modem was connected,I would get "Line to noisy" when checking for load coil. On a test it would knock out the DSL and I would stop pinging and the the DSL would sync up again with the same ip address and resume pinging. If I disconnected the modem and tried I would not get test results and get no data msg. I ended up using an old Efficient 5360 modem and put a splitter at the jack on the modem. I connected the 1200 into the splitter with a banjo. I had the DSL connected and was pinging to verify connection. I then ran a test and it showed no load coil. I showed data. I tried testing and got the results that were comperable with a speed test that I then performed. I am not sure why I can not test from the DEMARC straight out without a modem connected, why I can not test while the 5100 modem is connected, Why I am getting too noisy while the 5100 modem is connected. It could be my home wiring for the phones which was done in serial, It could be that I am getting DSL from an RT and not from the CO directly, It could be that When the 510o is conected it creates problems. I will still have to play around to get the answers. I do know that the test unit does work though which was a big concern as I bought it used.