Search some of Ted's post's he has posted a way to disconnect the gala with out disrupting the speed signal. Its just a mater of where you cut.
If you can't tune off of 25 then the tuner isn't receiving any channels.
Note I have the B tuner so I hope this all relates.
I am guessing you are in North America, if you are set to NTCS you should see snow with no sound. If it is set to PAL you will get a blank screen and no Audio. Make sure you are using the correct mode. I believe pin 7 of the wires coming from the NAV unit changes it from NTSC and PAL. I can't help much beyond that because I haven't worked with a non B tuner. This is definitely where I would be looking though.
David
If you can't tune off of 25 then the tuner isn't receiving any channels.
Note I have the B tuner so I hope this all relates.
I am guessing you are in North America, if you are set to NTCS you should see snow with no sound. If it is set to PAL you will get a blank screen and no Audio. Make sure you are using the correct mode. I believe pin 7 of the wires coming from the NAV unit changes it from NTSC and PAL. I can't help much beyond that because I haven't worked with a non B tuner. This is definitely where I would be looking though.
David