This one has me baffled. I have been with DTV since 1996 and have never had an issue. I have a triple LNB. I have an HR10-250 and a Sony SatHD-300. The HR10 works fine on all channels. The HD300 works fine on all channels EXCEPT the HD channels 70 - 94. When I tune into channel 70 (HBO) it works for about 1 minute then goes to "searching for satellite signal". I reset the box and I am fine again except for HD. The confusing thing is that all 3 sats show signal strenghth from a low of 82 to a high of 93. I have no issues with the HR10-250. I even went up and switched the line to the other two ouptuts on the 4X4 multiplexer to see if that was the problem. It is not the multipelxer because I have the same issue.
Is this a problem with the Sony SATHD-300?
If its not the signal, not the multiplexer and is the STB why do all the channels work except the HD channels?

Any advice would be appreciated and prevent me from drinking at 2:00 in the afternoon!!

"Is this a problem with the Sony SATHD-300?"

I think you pretty much ruled out any other problems, may be time for a new receiver. I have an HTL-HD which is a mechanical clone of the HD300 and the LG 3200A hooked to a triple LNB dish and the HD channels are fine on it.

This one has me baffled. I have been with DTV since 1996 and have never had an issue. I have a triple LNB. I have an HR10-250 and a Sony SatHD-300. The HR10 works fine on all channels. The HD300 works fine on all channels EXCEPT the HD channels 70 - 94. When I tune into channel 70 (HBO) it works for about 1 minute then goes to "searching for satellite signal". I reset the box and I am fine again except for HD. The confusing thing is that all 3 sats show signal strenghth from a low of 82 to a high of 93. I have no issues with the HR10-250. I even went up and switched the line to the other two ouptuts on the 4X4 multiplexer to see if that was the problem. It is not the multipelxer because I have the same issue.
Is this a problem with the Sony SATHD-300?
If its not the signal, not the multiplexer and is the STB why do all the channels work except the HD channels?

Any advice would be appreciated and prevent me from drinking at 2:00 in the afternoon!!
Have you set the 300 to the 3 LNB Dish? Go thru the set up menu and check
Are you subscribing to the HD Channels?

Thanks
Yes, it is set to 3 LNB and yes I am subscribed to the HD channels. I have a second STB, the HR10-250 that is working fine which I would think confirms it has nothing to do with the dish,LNB's or mutiplexer. I am confused why all the other channels work fine on the Sony, which to me would mean the STB is working.....................baffling.

I have a Sony HD 300 that had the same problem and had to send it in to be repaired. in my case it I believe they said it was heat breaking down one of the components.