Welcome to the forum. New UTV members are a nice sight.
If you have additional UTV questions or comments we are here to talk about them. The UTV FAQ is an excellent resource so be sure to give that a read to help get the Basics.
If you haven't already... Making sure your UTV is staying cool (internal fan working and vents clean)... is out in the open and maybe elevated (Plastic Bottle Caps are popular) slightly is an excellent way to keep heat problems from effecting the picture.
With that taken care of an occasional "reboot" (power down or reset code) and/or a few minutes/hours/over night cool down... Is helpful in resolving many "odd" glitches. Microsoft once recommended a reboot ever month or so... I personally do it randomly when I remember too...
If you are concerned that a Tuner may be going bad... You may want to spend a few minutes looking at your UTV's Signal Strength Menu and the History Log (in My Shows) to see if there have been/is unexpected Tuner Status changes. If your Dish has a clean shot at DTV... It's just a matter of figuring out if the problem is with the LNB,Cable Run(s),Multi-Switch, or UTV itself.
Let us know what you discover and get back to us... We can help troubleshoot a possible Tuner problem if that is it.
Outright Hard Drive failures are obvious... so hopefully it's just a heat related problem and a simple fix.