The power supply board to your tV is faulty. The sound you heard is due to a bursted capcitor. If you are aware in electronics and efficent in servicing LCD TVs, open your tV and locate the switching power regulator section. Look for any bulged or bursted capacitors in it. If is there, replace it with same capacity and size. Its capacity will be mared on it body intself in MFDs units. I hereby attaches a picture [not the power board of your TV; but to know you what a bulged capcitor will look like.
Look at the red arrow marked capacitors. They are all damaged [bulged] ones. You can see a good one at the top right of the baord. The only repair work that can be done with power supply of LCD TVs are, replaceing these types of capacitors if any. If you cannot see any of them like this in your TVs power supply [the picture of Sharp LC series LCD TVs power supply is attached below]; the pop sound you heard is from the switching transformer. It is very difficult to replace them and very rare to get from open electronic spare part market. if this is the case, you have to replace the power board as card basis, and it is good too; rather than making "surgery" to it.
This is the power board to your TV. As you can see, it will be very difficult to replace any component to it, and you must have a good concept of desoldering and soldering and equipments ot do the work. After replacing the power supply some adjustments to it should be done to accept the new power board to main system board. In rare cases, the main system board will accept the replaced power board. If so you are lucky. If you haven't enough knoledge in this matter, get it repaired by any well experienced service techinician or by the authorised service center for Sharp at your town
If you want any more assistance from me, feel free to get me by Fixya. OK.