LC-70UD20KN (serv.man5) - Sharp TV User Guide / Operation Manual. Page 77

•  No power.

•  Is the AC cord disconnected?
•  Check if you pressed 

a on the TV.

•  The TV cannot be 

operated.

•  External influences such as lightning, static electricity, etc., 

may cause improper operation. In this case, operate the TV 
after first turning off the power, or unplugging the AC cord 
and re-plugging it in after one or two minutes.

•  Remote control unit 

does not operate.

•  Are batteries inserted with polarity (

e, f) aligned?

•  Are batteries worn out? (Replace with new batteries.)
•  Are you using it under strong or fluorescent lighting?
•  Is a fluorescent light illuminating to the remote control 

sensor?

•  Picture is cut off.

•  Is the image position correct?
•  Are screen mode adjustments (Wide mode) such as picture 

size made correctly? (Pages 43, 56 and 57)

• Strange colour, 

light colour, or dark 
colour, or colour 
misalignment.

•  Adjust the picture tone.
•  Is the room too bright? The picture may look dark in a room 

that is too bright.

•  Check the “Colour system” setting (Pages 40 and 45).

•  Power is suddenly 

turned off.

•  The TV’s internal temperature has increased. Remove any 

objects blocking the vent or clean.

•  Is the “Sleep timer” set? Select “Off” from the “Sleep timer” 

menu (Page 37).

•  Is “No signal off” or “No operation off” activated? (Page 37)

•  No picture.

•  Are connections to external equipment correct? 

(Pages 24

_29)

•  Is the input signal type selected correctly after connection? 

(Page 44)

•  Is the correct input source selected? (Page 16)
•  Is a non-compatible signal being input? (Page 59)
•  Is the picture adjustment correct? (Pages 33

_35)

•  Is the antenna connected properly? (Page 7)
•  Refer to “Picture / Audio test” (Page 77).

•  No sound.

•  Is the volume too low?
•  If you do not clearly hear the sound for the visually impaired, 

go to “TV Menu” > “Setup” > “Audio” > “Audio description 
setting” > “Mix level”, and select the upper level to turn up 
the volume.

•  Make sure that headphones are not connected.
•  Check if you pressed 

e on the remote control unit.

•  Is the proper item selected in the “Audio select” menu 

when connecting devices to the HDMI 3 terminal or the PC 
terminal? (Pages 25, 44 and 57)

•  Refer to “Picture / Audio test” (Page 77).

•  The TV sometimes 

makes a cracking 
sound.

•  This is not a malfunction. This happens when the cabinet 

slightly expands and contracts according to changes in 
temperature. This does not affect the TV’s performance.

•  Net TV start page 

cannot be displayed.

•  Is the ETHERNET cable connected correctly? (Page 62)
•  Check the settings of “Network setup” (Pages 62–63).

• Some Internet 

functions used on a 
PC are not available 
from the TV.

•  The TV has only limited functions compared with regular PC 

browsers (Page 64).

• Miracast image/audio 

cannot be output to 
the TV.

• Check pairing.

•  When the TV is used in a low temperature space (e.g., room, office), the picture 

may leave trails or appear slightly delayed. This is not a malfunction, and the TV will 
recover when the temperature returns to normal.

•  Do not leave the TV in a hot or cold location. Also, do not leave the TV in a location 

exposed to direct sunlight or near a heater, as this may cause the cabinet to deform 
and the LCD panel to malfunction.
Storage temperature: 

f 20 °C to e 60 °C.