Question about LG M4200C 42 in. HDTV-Ready LCD Television

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Channel box appears on screen with "Mono" flashing. When this appears on screen remote will not operate tv. Also, if TV is turned off will automatically come back on in about 5 to 10 minutes

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Re: Channel box appears on screen with "Mono" flashing. ...

I have a similar problem with my LG LCD TV Model 42LC7D. Manufacturer has service bulletin on my problem, may have service bulletin for your problem also.

Posted on Jul 19, 2007

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Televison station won't scan

If you are receiving a "No Signal" error message, verify that:
  1. All of the cables physically connected to the TV and the input device are secure.
  2. The input device is turned on.
Your TV needs to scan for channels before it can show programming from an antenna, from cable TV when the cable comes directly from the wall (no cable box), or from a cable or satellite box connected to the TV with a coaxial (RF) cable. Do not scan for channels if you have a cable or satellite box connected using AV (Composite), Component, or HDMI cables. The box selects the channel, not the tuner inside your television. If you are not using the "TV" input, press the INPUT button on your remote until the correct input mode is selected.
To perform a channel scan using the coaxial input:
  1. Press the INPUT button on your remote to view your current input source. The TV (coaxial cable) input must be selected. This may appear as "TV," "ANT," or the channel and call letters of a station.
  2. If the TV input is not selected, press INPUT until the TV input mode is selected.
  3. Open the on-screen menu and select TV or Tuner option. (This varies by model.)
  4. Highlight Tuner Mode and select the correct option:
    • Antenna-over-the air signals from an antenna
    • Cable-direct from the wall cable TV, or a cable or satellite box connected to the TV with coaxial cable
  5. Select Auto Search or Auto Channel Scan. (This varies by model.)
  6. When the search reaches 100% complete, exit to the menu.
  7. Check the available channels:
    • Antenna or direct-from-wall cable-Press the Channel Up and Channel Down buttons on your VIZIO TV remote to view the available channels.
    • Cable or satellite box- Will return only one channel. Use the cable or satellite remote's Channel Up and Channel Down buttons.
If this does not resolve the issue, power cycle the TV and then re-run the channel scan:
  1. Turn off the TV.
  2. Unplug the TV from the electrical outlet.
  3. While the TV is unplugged from the wall, press and hold the Power button on the TV for 30 seconds.
  4. Release the power button.
  5. Plug the TV back into the electrical outlet.
  6. Turn on the TV.
Note: There is also an option to reset the TV to the factory default settings. This option is in either the SETUP or SYSTEM section of the on-screen menu. The option may be "Reset all settings", "System Reset," or "Reset & Admin." Consult your TV's user manual for the location and steps for resetting your model.
  1. Remove the coaxial cable from the DTV/TV connector on the back of your television and perform a channel scan to clear the existing channels. See the procedure above. This should not find any channels.
  2. Re-attach the coaxial cable to the DTV/TV connector and perform a new channel scan.
This video shows troubleshooting steps to use when a "No signal" message appears.

Jun 25, 2014 | RCA 46 46LA45RQ LCD TV

1 Answer

Atv will turn on but stays on one channel and menu button and channel button will not work, and there no picture.

Most TV's require to be set on channel 3 with the TV remote again I say with the TV remote then if you get a screen run the channel lookup command from the TV remote, that should do it for you. In addition make sure the TV is set to the correct AV input with the converter box remote, your ISP can help with that part
Good Luck Ed Pinero

Feb 05, 2013 | Sony BRAVIA KDL-52S5100 52 in. LCD HDTV

1 Answer

No signal onthe screen

If you are connected to a high definition cable box or satellite tv box you would not need to turn to channel 3 on your television. The television would need to be in the right input either component or hdmi. If someone connected the tv to the cable box or satellite tv box with a coax cable like an antenna cable then the tv channels will be available on channel 3 as well but they will not display in high definition. You change channels with the cable box/satellite tv box remote control. If the above is not correct and you are only connected to an antenna cable and not to a cable box or satellite tv box you will need to complete a channel search from the tv menu. It sounds like you are using a cable box/satellite tv box and that the tv is on the wrong input. If the cable box/satellite tv box is not working (i.e. just a black screen) on your television than that is a different matter entirely.

May 10, 2010 | Samsung LE32R41BD 32 in. HD-Ready LCD...

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No sound on some channels, other channels fine

Your SAP/MTS function is most likely turned on. This feature has 3 modes: Stereo, Mono and SAP. Stereo and Mono are easy to understand, it's the SAP that can get you. SAP stands for Second Audio Production. It is used to provide weather, information or an additional language translation of a program. Some broadcasters simply transmit the mono audio over the SAP audio channel when the are not using it for other purposes. Other broadcasters simply do not use it, which does not give you any audio. Look on your remote for a SAP or MTS button. If you do not see one, look in your TV user menu for this feature. If you are using a cable box, look in the audio menu of the cable box. You are looking for something set to SAP... just change it to STEREO. I hope this was helpful.

Mar 26, 2010 | Flat Panel Televisions

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My Sharp Flat Panel Television LC19SB25U has Picture but No Audio

Sharp has had a few problems with their audio boards, not finding any bulletins on this model, but a few complaining about low audio on amazon reviews section. If using an antenna you will experience some channels with low audio. If using cable you should get good sound on all channels..
the 9.1 and 9.2 are digital channels and sharp does display them for at least a few seconds when you switch to that channel. Check all your setting in the audio to Stereo never SAP. To options for you are get a cable box, first check in the back and see if there is another coax in, if there are two try both rescanning after connecting.
GD lk

Aug 16, 2009 | Sharp LC-19SB25U 19 in. LCD HDTV

1 Answer

TV freezes when switching to a digital channel

The problem your describing can be contributed to your cable box. Depending on your cable company there are times when the box has trouble translating the signal to the tv. You tv is operating normally. Suggest to the cable company to switch your box.

Dec 05, 2008 | LG 32LG40 32 in. LCD HDTV

1 Answer

Sharp Aquos LC-37D62U Audio Warning

Usually the settings can't be turned off and the audio settings are searching for whatever is being outputted from the program itself whether mono or stereo. It is nuisance I know.

Jun 28, 2008 | Sharp Aquos LC-42D62U 42 in. LCD HDTV

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Cannot change channels in digital mode

Solution that worked for me:

Beware: Although the process should be safe, it technically voids your warranty.

Enter the service menu:
1 - turn of tv with remote
2 - press and release in the following order on the remote: Info, Menu, Mute. Make sure remote is pointing at the tv
3 - turn on the tv from the remote
4 - you will see the service menu. using the down arrow on the remote select the Reset option. Using the right arrow button at this point will do a hard reset.
5 - Wait a few seconds, turn TV on
6 - you will have to rescan analogue and digital channel but it should be working now.

Jan 29, 2008 | Samsung LE26R73BDX 26 in. HD-Ready LCD...

2 Answers

Green box keeps popping up in upper right corner

You should be watching your dvd's on an input and not on tv analog 3. Every time the tv "senses" a signal change in the audio that screen will pop up. Connect the DVD player to the tv by using either the red, white and yellow (composite) connections or using the green, blue, red, white and red (component). Once you are on an actual input that box will stop popping up.

Dec 27, 2007 | Sharp Aquos LC-42D62U 42 in. LCD HDTV

1 Answer

SAP - I can't get my new TV out of Mono and into stereo.

Are you using a cable box sush as a Comcast cable box? If so then the volume control within the cable box is most likely not high enough for the TV to detect a stereo pilot signal. The Comcast remote (if thats what you have) still is programmed to operate the volume within thier box, the volume display will be at the top of the picture and it will be in white. Turn it up until the word "stereo" appears. then leave it at that setting and use your TV's volume control only.

Feb 13, 2007 | LG MU-42PM12X 42 in. HD-Ready Plasma...

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