JVC LT-42X579 42 in. LCD TV

SOURCE: Picture blacks out after a few seconds after turning on the tv

Anytime an LCD has a shade of pink, that means the CCFL lamps are about to go out. Now that you have a black screen, I'd say you just need some new bulbs.

SOURCE: JVC LT 42x688 no picture just sound

Sorry, this has no easy fix. The good news is you do not need an LCD Panel. The bad news is the Video Processor has a problem.
This TV has x3 Boards. The one you should replace first is the one in the middle. If this doesn't fix it, try the one on the right. The Part #s are on the Boards if you wanna try ebay.

SOURCE: JVC LT-32DS75SJ issue with HDMI

Try this

1. Turn ON TV
2. Connect PS3 to TV HDMI input
3. select TV HDMI input for PS3
4. turn OFF PS3 if it is ON
5. Press and hold the [I/O]Power button until the PS3 until you get the "HDMI Detected" message.

Also, this TV has a circuit that deactivates the HDMI if the rear cover is removed. It is possible the HDMI may have been turned OFF. This is reset in the service menu of the TV.

SOURCE: JVC LCD TV LT-42X688-powers on, blank screen. no picture,no sound

Hi , I have the same problem with my LT-42X688,so i called the service of my extended warranty provider . the TV technician just left and told me the motherboard is the problem. he said its the third one this week he has seen with the same symptoms. he ordered the motherboard and i've got to wait 5 to 7 work days before the part will be in . I will keep you posted when the guy will return.

SOURCE: All of the HDMI ports on my JVC lcd tv are not working.

I had the same problem on mine. It is a factory defect. It means your HD box that controls HDMI, USB, and RED GREEN BLUE component. Usually the red, green, blue, (720 HD) component is still functional, but the HDMI and USB are shot and can only be replaced not repaired. If your warranty is still valid and you have your receipt call JVC and they will give you the number to a certified warranty repairman. If you do not have the receipt they will not fix it. If you do not have the warranty and decide to repair it yourself or send it out, the fix is not difficult but it is costly. The box is about $1000.00 and the labor varies. The last option is to sell it for parts. If you decide to do this I will purchase the broken television from you. But if you have your warranty info there is nothing to worry about.