Screen is dull at startup and darkens futher when brightness is increased then flickers for a while and may go black or turn to normal. once normal it stays so untill computer is switched of. when flickering, it continues even without input.

Failing Inverter An inverter, typically found inside a laptop computer, consists of a small board, which has impregnated electronic circuits stamped on it. Inverters look like thin boards about the of two sticks of chewing gum. The inverter and its bulb control the intensity of the liquid crystal display, which lights the screen monitor. The computer can control the output voltage of the inverter and either lighten or darken the screen. A special type of inverter can adjust the brightness of the screen by using an internal sensor to judge the room brightness, and then adjust the screen accordingly. Failing inverters give off some specific warning signs, which can be recognized by observing different screen characteristics.

Short Intermittent Display Upon turning on the laptop, the screen flashes on in the normal mode for a short period and then blinks to black. A very faint image appears in a dark background, which will be very hard to see almost invisible. After shutting off the laptop and restarting, the same mode occurs, where the screen appears normal for a few seconds then fades to black. This condition points to a failed inverter. To confirm this, plug in an operational external monitor; if the external monitor functions, the inverter has failed. b> Total Blackout with Ghost image b> The laptop turns on, as indicated by the power supply button, but the screen comes up black. The screen comes up black after restart. You might be able to detect a very dim or ghost-like image on the monitor. When you plug in a known functioning external monitor, the external monitor operates normally. This mode of display indicates a failed inverter. b> Long Term Periodic Operation b> With this failure mode, the laptop screen illuminates normally upon start-up and remains that way after several minutes, hours or even days, until it goes very dark again. Brightness controls or restoration attempts do not work. Most often, the screen will function normally with a computer restart, but will eventually return to black. Faint ghost images might appear, as seen in the total blackout mode. b> Dark With Color Variation b> Upon computer start-up, the monitor shows black or dark gray, accompanied by very faint images. The screen might have an intermittent color change, or remain on with a non-standard color variation, like pink or red. b> Auto Control Switch b> If the screen appears black, with no faint or ghost images, look for the lid switch near the back hinge. The switch, when depressed with a closed lid, shuts off the computer and monitor functions. Sometimes the switch becomes stuck in the closed position, disallowing the computer and monitor to turn on when opened. Pushing the switch manually several times can often free it up. If the switch tab has broken or jammed inside the case, it needs replacing. b> Loose Connection In this mode, the display looks normal upon start-up, but tapping the side case of the computer turns the screen black. More tapping results in the screen functioning normally then cutting out again. This condition points to a loose wire connection from the inverter to the LCD backlight lamp, or the video cable. The connectors can be accessed by removing the monitor bezel screws and pulling the plastic retainer off. Both connectors can be cleaned and refitted.

he Dell I'm using also has an adaptive brightness, regardless of the fact it does not have a light sensor. It just changes brightness of the screen depending on how much white/black is shown at that moment. Whenever I switch from a very dark to a very bright website I notice and increase/decrease in screen brightness. I'm running Windows 7 by the way.
Good Luck

You have the unit in dark mode. Press the Dim/Dark button again to get the unit to full brightness. THe unit has 3 levels of DIM. First the unit is at its full brightness, pressing the dim/dark button will dim the display and the unit functions normally. Press the Dim/Dark button again will futher darken the display but when the unit alarms the display is turned off and remain off during the alert. After the alert is over the unit waits 20 seconds of no alert to turn the display back on.

try to use the auto adjust button. if it doesn't work you have to go to the nearest service center in your place

Since you have replaced the Color Wheel, it sounds like you have not adjusted the Index Delay in the service menu. First reset all of the picture settings you have adjusted back to original factory settings. Then on your Samsung TV Remote and with the TV OFF, Press Mute,Power,123. This will turn on the set and put you in the Service menu. Look for the top setting and select or scroll to the OPTION setting and select and look for INDEX DELAY and select that. Once you have the Index Delay selected use the right and left buttons on the remote to adjust for a picture the has no abnormal coloring and while looking at a program adjust for when the blacks look black with no abnormal coloring. Once that is done, turn off the set then turn the set back on. Now the picture should look normal.

check the flyback transformer turn a little bit clockwise the screen knobs this will help to increase a little bit brightness. beware of HV do not touch the wires, This is due to old CRT or FBT need replacement.

The screen brightness is automatically adjusted by your laptop's Power Management configuration in the Control Panel. Depending on your laptop's brand you might not only have the Windows power management, but also a proprietary power management application within the control panel or in your Start Menu programs usually listed under your computer's brand name. For example a program folder called "Toshiba" under Programs for a Toshiba laptop. Anyway, I would start there. Usually you can set up the screen brightness according to whether or your computer is plugged in or working on battery. Good luck! :)

Im sorry to tell you that the inverter its broken, you need to buy a new one and change it. Is not the display its the inverter, and also in some rare case you will need a new flex, try in ebay and buy it the piece that exactly much your notebook and take it to an expert to change it. I hope it serves

pd sorry my english,.

Startup while tapping the F8 key,this should open the startup options screen,Select start up in VGA mode,If that works,then you need to update the video drivers

<Fn> + <→> Brightness up Increases the screen brightness.

<Fn> + <←> Brightness down Decreases the screen brightness

If tese dont work either your LCD lamp or board may be going bad.