You most likely have the wrong cable. The pinouts for the HK TC1000 and the IRIQ are in a file here on Remote Central.

[Link: remotecentral.com]

I would definitely check that cable with an Ohmmeter before using it.

If you need a cable you can make one, or send me an email I probably have an extra.

The cable for the Home Theater Master MX850 just happens to be the same as the Take Control cable too.