M4300 some colours pinkish, other colours OK

Dell SupportAssist could do a stress test on the Nvidia GPU.  When the GPU's temperature went over 85 degrees Celsius the entire screen became OK.  But when the GPU reached 87 degrees the fan came on, the GPU dropped back to 83 degrees, and parts of the screen that were supposed to be white became pink again.

As impressive as the stress test looks, it doesn't detect the result.  On a mostly pinkish background, it shows the word "Passed."

Hi NORMAN DIAMOND,

Run the LCD bist - Turn off the system and press and hold the "D" key + power button to turn on the system and it should run the LCD built in self test - see this link for more info - http://dell.to/1SkXNrG

Restart the system and press f12 key on startup - choose diagnostics. Let it run the diags and if you encounter any errors - make a note of the complete error and report the same to us. These are onboard diagnostics and they might possible pick some error if the hardware is not functional.

Check for the distortion while running the above tests.

Connect an external monitor and check if the display is fine on the external monitor.

This will help isolate if the issue is with video card or the LCD. 

Based on your description of the stress test, I suppose the issue could be more likely with the video card.

Also, please click my DELL-username and write me a private conversation with the service tag and your Name for case records.

Let us know if you have any other queries.

"hold the "D" key + power button to turn on the system and it should run the LCD built in self test"

It did, and there was no visible problem.  It didn't display any messages or questions but proceeded automatically to start booting, so I pressed the F12 key to run general diagnostics.

The general diagnostics were the same from holding the Fn key when turning on the power.  As suggested in the page you linked to, when those diagnostics displayed colour bars, I pressed N to say the bars were not displayed correctly (even though they actually were).  It proceeded to test the LCD in the same way as when I held the D key, again with no visible problem.  Then it displays Error Code 0334, Msg: Error Code 2000-0334, saying the user reported that graphics problems were no displayed correctly.  In other words, the diagnostics did not self-find any problem, and I did not see any problem during the graphics test.

I told it to retry and again there was no visible problem in the colour bars, so when it asked again I said Y.  It's proceeding to memory tests and the screen is correct now, the progress bars are white not pink.

But the problem is intermittent.  When Windows is displaying an ordinary window like Firefox displaying Facebook, there are some regions with white backgrounds, some with gray backgrounds, etc.  Some of the white backgrounds get displayed as pink -- sometimes.

If it were the LCD, I'd expect to see wrong coloured lines across the entire width or height, not depending on what colour Windows (or the BIOS's memory test) was trying to display.

So I think it's an intermittent problem in either the video cable (which I have enough skill to try replacing) or the Nvidia controller (which I don't have enough skill to reflow or replace).

Dell-Rishi, I tried twice to send you a private message containing the service tag.  Dell's messaging system behaves strangely so I can't guess if the messages reached you.

Hi NORMAN DIAMOND,

Thank you for the update.

I have received your private message.

Since the issue is intermittent and seen while in BIOS and diagnostics, it could either be the video card or the LCD.

However, I would more likely suspect the video card as you have previously stated that the issue occurs when the GPU hits a certain temperature. 

It would be much easier to determine the source if you used an external monitor. 

You could contact our team to get a quote for a paid service call - http://dell.to/1vnT6CQ

Since the system model is obsolete, I am not sure if Dell would have the parts required to be replaced.

You could also order the parts here - http://bit.ly/2gtfsVW

Let us know if you have any other queries.

"However, I would more likely suspect the video card as you have previously stated that the issue occurs when the GPU hits a certain temperature."

The issue STOPPED when the GPU hit a certain temperature.  It started again when the fan went on and pushed the temperature back down.

Nvidia's driver includes a control panel that lets us set brightness, contrast, gamma, digital vibrancy, and hue.  I partially understand each of those.  I reduced the brightness a bit and the problem went away.  I increased the brightness a bit and the problem came back.  So my wife is using it now with the brightness reduced a bit and it seems to be good enough for her.

You're right that I should have tried an external monitor but now we know it's the controller.

Hi NORMAN DIAMOND,

You could try updating / flashing the BIOS - http://dell.to/2gzf4GC

Also, try updating the video drivers from the vendor site here - http://bit.ly/2feutpS

Word of advise - create a system restore point before you reinstall the drivers, so that in case there is any issues, you could always restore the machine back to the most functional point.

Let us know if you have any other queries.

I agree that reflashing the BIOS has a chance (a small one) though it is already the last version.

Updating the video driver will not help.  When the BIOS's memory test had its progress bars pink while text was white, Windows and its drivers were not active.

Furthermore Nvidia's latest driver update sets the screen to 100% black (when Windows is running).  Luckily five repetitions of boot - power off by power button - boot - power off  and repeat puts Windows 10 in boot recovery mode so I could put it back to the previous day's system restore point.

I didn't get a chance to reflash the BIOS before it got worse.

The new failure is hard to believe.

Thank you for pointing me to the LCD test which can be obtained by holding the D key when powering on.  This test still works.  It illuminates the entire LCD in a series of solid colours.  So the LCD and cable are OK.  But does this also test the Nvidia chip and the BIOS?  Does it tell us that the Nvidia chip is working?

Holding the Fn key when powering on enters diagnostic mode but the screen is solid black.  The keyboard's three LEDs (NumLock, CapsLock, ScrollLock) flash for a few seconds and then it changes to only CapsLock flashing, so I think the BIOS is executing diagnostics.  However, the DVD drive's tray doesn't open and there are no beeps telling me to look at the question of whether stripes appeared correctly.  After a while CapsLock stops flashing and NumLock comes on solid as it would do for an ordinary boot.

Last night my wife heard Windows boot tones while the screen was black, but when I tested later I didn't hear them.  But I forgot to try an ordinary (non-diagnostic) boot.

"This only tests the LCD assembly and not the video card."

That's a valuable test, thank you.  It only needs an addition:  display its resolution and model number on-screen while testing itself.

Today the BIOS start-up showed some text with random artifacts before going black, so yes Nvidia decided that Dell's BIOS update a few years ago wasn't sufficient to overcome Nvidia's quality problem.

I hate to waste a good WUXGA screen.  Someone's auctioning a Latitude D830 with low specs and low price but. working, until its Nvidia chip joins the club too.

Hi NORMAN DIAMOND,

You could certainly provide product feedback here - http://bit.ly/2gkFPti- the relevant teams shall look into it.

If you consider, you could choose to purchase refurbished Dell systems here - http://www.dell.com/learn/us/en/22/campaigns/outlet

Let us know if you have any other queries.