No display lights


My gateway laptop just lost its lights on the display works well but no screen lights On my laptop the light comes on and shuts down after about 6 seconds. It behaves exactly this way after whatever I do to engage it; turn the computer on, wake up from standby, press and release the "lid closed" detection pin, ...

There is a button on the keyboard with a light blue "Fn" on it. While holding it down I can adjust different settings such as illumination, contrast, etc.

I noticed at one occasion that pressing it right after engaging the light it shuts down prematurely (quicker than the 6 seconds I mentioned above).

So I tried to crank the illumination down and up to max (while the lights were "off"), press hold and release the "lid closed" pin and after a few attempts the lights came on and stayed on without shutting down again.

If the computer goes to standby or powersave or whatever that invokes it to shut down the display light I have to struggle this way again in order to revive it.

I also noticed that when adjusting the illumination, if I go below a certain threshold, the screen goes completely black. It seems like the lowest notches of the illumination control cannot supply enough voltage to run the display light although it doesn't show any signs of impairment once it starts working (e.g. abnormally weak light, yellowish color, flickering, ....).

Does anyone have any clue as to what is malfunctioning?

Run the PSA Diagnostics and Obtain the PSA Error Code

To run the PSA diagnostics and obtain the PSA error code, perform the following steps:
Shutdown the computer.

Press and hold the <Fn> key, then press and release the power button.
Release the <Fn> key when the lock lights above the keyboard begin to flash or Diagnostic boot selected is displayed in the upper right corner of the screen.

Release the <Fn> key.
The PSA diagnostics sequence begins.
After approximately 2 minutes the system produces a number of alert tones.
After the alert tones, the system produces either a series of low beeps or error codes.

Note:
PSA diagnostics will prompt for input during some tests. The resulting error message does not necessarily indicate hardware failure.
For example, input is required during the color bar test. Failure to input a response will eventually result in a timeout error: 1000-0333 Graphics test timed out waiting for keyboard response. This does not indicate a graphics failure has occurred.


Note the sequence of beeps or error codes.

Initialize LCD BIST Diagnostics



You can initialize the LCD Built-in Self Test (BIST) in two ways, depending on the revision of Pre-boot System Assessment (PSA) diagnostics:
PSA versions 3019 and greater run LCD BIST immediately after failing the color bar test, via user input of <N> or waiting for it to time out prior to generating the 3-3-3 or 3-3-4 error. PSA version 3019 became available in November 2005 on various Dell laptops. The PSA version is upgraded with the BIOS.

With older versions of PSA diagnostics prior to November 2005, LCD BIST runs after responding with a <Y> after receiving a 3-3-3 or 3-3-4 error code.
To initiate the LCD BIST on PSA versions 3019 and greater:
Boot to the PSA Diagnostics.
Watch the screen and listen for the color bar test prompt tones emitted by the PSA Diagnostics. If the screen is visible, one will see the PSA diagnostics draw a series of multi-colored bars across the screen. When completed, a prompt asking if the pattern was seen appears, accompanied by a brief series of tones.
Press <N> or wait approximately 30 seconds to fail the color bar test.
Watch for the LCD BIST color generation and listen for the beeps every 2 seconds that indicate LCD BIST is running.
LCD BIST runs for approximately 20 seconds, then stops. The 3-3-3 or 3-3-4 error code is then displayed when the LCD BIST is complete. If LCD BIST does not initialize, then the system may not have been upgraded to PSA version 3019.
To initiate LCD BIST on systems with PSA versions prior to 3019:
Boot to the PSA Diagnostics.
Watch the screen and listen for the color bar test prompt tones emitted by the PSA Diagnostics.
Press <N> or wait approximately 30 seconds to fail the color bar test.
The system emits a 3-3-3 or 3-3-4 PSA error after failing the color bar test. Wait for two iterations of the failure code and then press <Y>.
Note:
On a working LCD, the PSA diagnostics shows the following message:
Error Detected, continue testing? Yes or No or Retry.


Watch for the BIST color generation and listen for the single beeps that indicate LCD BIST is running.
Patterns of flashing color should appear on the screen. With every color change, an audible beep is heard. If the patterns of color do not appear, and the beeps are audible, an LCD failure may be the issue. If the patterns of color appear, a video card or motherboard failure may be the issue.
IF AN ERROR IS INDICATED, PLEASE CALL DELL SO YOU CAN SEND SYSTEM TO SERVICE DEPOT FOR REPAIR (WE'VE JUST TRIED TO ISOLATE ISSUE TO SEE IF ERROR IS CAUSED BY HARDWARE OR SOFTWARE, OR JUST SOME CONFIGURATIONS)

Thanks and Goood luck! =)


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