HDMI connected LCD TV says "No Signal" After coming out of suspend/sleep mode

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http://ubuntuforums.org – Dear forum, I currently have a Sony LCD TV to use as a desktop monitor along with Ubuntu 12.04 LTD, an ATI dedicated graphics card, and an AMD Phenom II processor. When I turn on the computer, everything is fine with the monitor, but after I leave it in suspend/sleep mode, and then get out of sleep mode by moving the mouse, the fan turns on and the computer goes out of sleep mode, but the monitor says "No Signal". I tried unplugging and replugging the HDMI cable from both sides, but all that disconnecting the cable does is it makes the Sony LCD TV say "Check signal cable". (Hardware)