LCD panel is perfect with no dead pixels, however: When you switch it on, screen comes up briefly, then goes off, with flashing red light. LCD TV Sharp LC-42DH77E model any help very much appreciated?

replace the all 33000uf/35v capacitor from power supply pcb ur set will be the ok.

Sounds like display panel fault. If you wish to get some details; check the site linked here. Pull up older posts. Surf the site with patience. http://electronicshelponline.blogspot.com/
Faults & possible causes to LCD screen are given with illustrations. You can get an idea about the fault to an extent.

Watch the red light and or power light when this happens, if there is a specific number of blinks and then a pause that is a error code.

the transformer for the backlight is usually what fails on the elements especially if the logo comes up briefly then the screen goes out. I would check the transformers.

I assume this is related to your LCD monitor.
I think you mean dead pixels. The LCD monitor has tiny pixel elements, one for each red, blue, green color and each one of these colored pixels are turnes on by a transistor. When a transistor fails then the colored pixel it controls does not light up. This is a dead pixel and it shows up as a tiny black dot.
If the screen displays a blue screen, a dead blue pixel will appear as a tiny black dot in the blue screen.
You normally would not notice a few dead pixels unless they are grouped together.

If you are sure its not a stain. then its a dead pixel on your monitor.. sooner or later it will spread out. To be sure if its a dead pixel, run your monitor in different colors, black screen, green, red and blue.. If the spots stays then its dead pixel.. You will be replacing the lcd when time comes that it spreads out.

Hello,
I hate to be the bearer of bad news but this is actually one of those known and predicted issues with LCD televisions. What these are called are "dead" lines of resolution aka dead pixels aka frozen pixels.
This is one of the flaws of LCD televisions, there is a completely random, unpredictable fail rate of LCD pixels in all panels, the likeliness of failed pixels varies depending on the quality of the panels used in the TV.
There really isn't a resolution to make them go away, if they are simply frozen, usually a light (VERY LIGHT) tapping of the screen at the top and bottom points of the line will refresh the pixels. If they are coming and going more often, it means that the panel is weak or malfunctioning in those areas and you need a new panel in the TV. Unfortunately it's quite an expensive repair, running at least $400 USD, if you are within warranty period (usually only 3 months for dead lines of resolution.. but it varies up to 12 months depending on the manufacturer) I would suggest calling Vizio and inquiring about a replacement TV. They generally won't allow a repair as it costs them less to simply give you a new unit all together.
My apologies for your bad luck!

Not all flat panel displays are perfect. You probably have dead pixels in your display. You need to check with your retailer to see what the warranty on your display is. Some units come with a zero dead pixel warranty, while others will not allow you to replace the display unless you have more than a fixed number of dead pixels. Your retailer should be able to furnish this information to you.

The lines appearing on your LCD means it has a defect on the screen.

There are 3 types of pixel defect
1) dead pixel - pixel is always off
2) stuck pixel - pixel is always on
3) hot pixel - pixel is on but in red, green, blue or yellow, can also be a light black color

You can try to fix stuck or hot pixels but dead is dead.
1st method, flashing different colors rapidly:
JSScreenfix.com has a great tool. This is their free java applet or you can download it below.

2nd method, applying pressure to pixel:
Damp paper towel, Small stylus or dull pencil.

3rd method, tapping the pixel:
Pen with cover on or another small, blunt object.


If your laptop is still under warranty, get it replaced. If not you are looking at the most expensive part in a laptop to get replaced. (LCD screens on laptop is roughly equivalent to 40-60% of the total laptop cost

Please rate this if it this helps.

i think your capacitor is blown, do a google search for insignia, lcd, capacitor...
you can buy another one for about $2 but its a pain to install, you can also instead buy a new powerboard for about $80, its an east install and you wont blow more capacitors
bestbuy.partssearch.com