We have installed the optional keyboard on our 500T1C tablet, but it won't lock onto the tablet and we lose connection, so that the keyboard doesn't work.

I have a 55" LCD I purchased new a little over 3 years ago. The picture suddenly went blank. Turns out that none of the HDMI ports seem to work. When trying to change the source input, the active HDMI port will briefly appear in the option list and then disappear repeatedly. The analogs work fine. I've tried cutting power to the tv for a few minutes to reset but it made no difference. Anybody else experience this? What was the fix and how costly?