I previously had problems with this TV and Ubuntu - had to turn off the TV momentarily for the POST screen to come up. As soon as I turned it off I could hear hd activity, then I could turn it back on and the boot process would finish. This led me to suspect that there was a problem with the motherboard so I replaced it with an 880G Pro3.
At first the 880 couldn't see the POST or BIOS screens unless I used a VGA cable and then a new BIOS was released which worked better - I was able to see 1/4 of the screen at a time but at least I could navigate.
Since 2 different boards displayed similar video problems I now assumed that the problem was incompatibility due to the age of the TV.
found new hardware followed by Windows could not load drivers for this device. Apparently the 970 thought that the HD-PVR (a USB device) was a hd.
I should mention at this time that none of the 3 ASRock boards above would allow hot plugging of SATA hds. I got around that by using a 3rd party application (HotSwap!) which allowed me to use an eSATA docking station.
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After a couple of months I found that the ArcSoft TotalMedia Theater (the media player) no longer opened but since I primarily used Windows Media Center I wasn't worried. Then the final straw. About a week ago the TotalMedia Extreme recorder software stopped working so in desperation I restored an Acronis backup image of Win 7 on the Biostar TF720 to a spare hd, slapped an AMD 545 CPU and 4GB DDR2 on the old board and fired it up. Guess what? Everything works flawlessly.
No more messages, all the recording software and hardware work, no booting problems, works with both Samsung HD TVs and no problems with hot plugging.
I've come to the conclusion that ASRock has serious issues with the PCI bus on at least the last 3 generations of motherboards. It's unfortunate since I've been an ASRock user since the 939Dual-SATA2 but now it's time to move on.
I already gave away the A785GXH/128M to a friend who doesn't record HDTV and I will soon be replacing the 970 Extreme3. The 880G Pro3 has also been having problems again booting into Windows 7 - takes 2 tries - but I'll have to live with that until I can replace it.
My advice to you as a former fanboy - stay away from ASRock.
Next build will probably be Asus or Gigabyte.
Bill