20 Most Recent JVC LT42P789 42 in. LCD TV Questions & Answers


Unfortunately, there is a limitation on the JVC LT47P789 digital optical audio out. This audio output does not get the signal from any HDMI source. This is described on page 49 of the user manual. The manual is available from JVC here: http://resources.jvc.com/Resources/00/01/14/YA653ien.pdf . There is a similar restriction for the analog audio output from the TV with the HDMI inputs.

If you use the component audio/video inputs on the TV from your set-top cable box and DVD player, then the optical audio output will work. Otherwise, you need to find a way to connect the audio directly to the receiver. Some receivers have multiple HDMI input ports. These then forward the video signal on their HDMI output to the TV. Another option is to connect the analog audio outputs from the cable box and DVD player to the receiver. This may require resetting the Audio output from these set-top boxes to keep from sending the audio over the HDMI cable. With the Cinemate, you might need some sort of audio input switch or an HDMI converter and switch that separates the audio from the video signal.

I hope this helps. Please add a comment with more information about your devices for ideas on how to work-around the problem with this JVC TV.

Cindy Wells

JVC LT42P789 42... | Answered on Nov 05, 2017


1. simultaneoulsy press and hold [menu] and [vol-] on TV side panel
2. press and release [power] on TV side panel
3. count to 5 and release[menu] and [vol-]
4. TV should have turned on
5. if not, unplug TV and press[power]
6. repeat from step 1 if the TV does not power on the 2nd time

JVC LT42P789 42... | Answered on Apr 23, 2017


Unplug TV for 30 seconds then plug back in. Then hold down the "menu" and "Volume minus" at the side of TV followed by pressing the power button like you would normally when turning on the set. This may get it back up and running if the problem is with the main board. If this becomes a chronic issue you will need to replace the main board. .

JVC LT42P789 42... | Answered on Feb 28, 2016


Fault in the main power supply regulator board. Check and replace damaged component/s at its main power regulator [SMPS] section circuit. Contact any service technician. If you wish to get some details; check the site linked here. Surf the site with patience. Pull up older posts.
http://electronicshelponline.blogspot.com/
It will be best to replace the power supply regulator board as card basis rather than making "Surgery" to it; which usually will make loss for both money and time. Even though you can make it right, it will cost around an amount equal to the cost of a new board; including the cost of (spare parts + service charge) More to say, most of the spare parts to it will be difficult to get from open electronic spare part market. This is true to most of the flat panel TV power supply boards; irrespective of its brand and screen size. Whichever the brand of it may be.

JVC LT42P789 42... | Answered on Apr 06, 2015


Mine did the same thing once. I think all I did was hit the setup on the remote, and let it run back through all the channels and then it worked just fine.

I hope this works for you.

JVC LT42P789 42... | Answered on Jan 15, 2014


Sounds like some problem with its back-light. Contact any serivce technician. Products powered by electricity should be serviced or repaired only by experienced professional technicians. Any attempt to service or repair the product by anyone else could result in serious injury or death. If you are not familiar with electronics, do not attempt to repair. Whether you suffer fatal electrical shock. Instead, contact the nearest service centre.

JVC LT42P789 42... | Answered on Jun 30, 2013


The blue light merely indicates power is getting to the TV. When you press the power on button, the defective power supply shuts the TV down immediately

JVC LT42P789 42... | Answered on Jan 06, 2013


If you go jvc .com enter your model # ,there is an article on how to reset the tv. First you have to unplug your tv for 10 secs., plug it back in and press and hold the menu and vol- buttons while holding these buttons in press the power button once, count to 3 and release the menu and vol- button. The lillte blue light should be on. wait for 40 secs. the picture should now come back on. This worked for me, I had the same trouble.
mike

JVC LT42P789 42... | Answered on Sep 16, 2012


1. Hold [menu] and [vol-] button on the side of the TV
2. while holding these, press the [power] button on the side of TV (NOT remote)
3. blue light comes ON and stays ON
4. wait 10 seconds then let go of [menu] and [vol-]
5. wait another 30 seconds and some type of picture should appear

JVC LT42P789 42... | Answered on Apr 06, 2012


Tv now turn on it have flashes of pictures a few sec.than dies and have sound left olny?Yes.Take the tv aparts.The tv power supply board,that the board where the power a/c cord plug int o it.Check the tv power supply board carefully for dying and dead capactors parts like bulging up or puffing up onto it tops.U have all tools.U know basic electronic.Check and replaced all those capacitors parts are bulging ups or puffing ups onto it tops must be replaced.If tv power supply board have no bulging or puffing capacitors parts on the tv power supply board.Then those 2 long board that call the LCD inverter boards are dead,these 2 long LCD inverter boards only job are to help provide a backlight to the tv LCD screen panel to produced a pictures.Or tries websites like Shopjimmy.com,Ebay.com to buy a whole new refurbish power supply or those 2 long LCD inverters board for the replacement.

JVC LT42P789 42... | Answered on Jul 02, 2011


If you go jvc .com enter your model # ,there is an article on how to reset the tv. First you have to unplug your tv for 10 secs., plug it back in and press and hold the menu and vol- buttons while holding these buttons in press the power button once, count to 3 and release the menu and vol- button. The lillte blue light should be on. wait for 40 secs. the picture should now come back on. This worked for me, I had the same trouble

JVC LT42P789 42... | Answered on May 09, 2011


You will need to do in-depth troubleshooting, please read below:
First, look at the screen in darkened room to see if you can see any slight glow from the screen, if it does, then the problem can be the T-CON (not getting the 12vdc) or the main logic board not feeding the signals to the T-CON board.
if not, next place to check will be the power supply module, make sure it has 24vdc which is required by the backlight inverter to work, the reason for not having 24vdc can be from bad DC filter caps (leaking/bulging top, high ESR) or short circuits in the inverter board which will cause the 24vdc supply to go into shutdown mode, so you may have to disconnect the power cable that feed the inverter board to see if the 24vdc will work without the inverter board hookup, you will need to apply about 3~4 amp of load to the 24vdc to make sure it can handle that. There are fuses on the backlight inverter boards also. So there is some troubleshooting you will have to do to find out the causes of the problem you are having.

If you are going to DIY and have proper tools, electronics knowledge, and know safety precaution then please read on:

Basic LCD monitor and TV troubleshooting guide:
http://www.fixya.com/support/r5093881-lcd_flat_panel_tv_troubleshooting_guide
http://www.fixya.com/support/r6150077-basic_lcd_monitors_troubleshooting
http://www.fixya.com/support/r7406380-tv_training_manuals
Failed TV and Monitors pictures: http://s807.photobucket.com/albums/yy352/budm
Learn about bad caps: http://en.wikipedia.org/wiki/Capacitor_plague
Parts: www.shopjimmy.com
Capacitors kit: http://lcdalternatives.auctivacommerce.com/Default.aspx he can make you a set of caps.
Or www.digikey.com, just make sure to use caps with low ESR, 105c, high ripple current and long life rating such as PANASONIC FM or FC series.

JVC LT42P789 42... | Answered on Apr 29, 2011

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