my dell latitude e6420 screen goes blank when it has to boot

Hi to everyone in the community,

I have  this same model E6420 as work laptop from my company for about 1 3/4 year. In this time twice the hard drive failed (Windows problem, recovered all my files with a Knoppix boot disk) every 1/2 half year and as I write this email just recovered from the described error above. I tried all the steps as mentioned to no avail. Then I downloaded the BIOS A21 update and used Knoppix to copy the file to the hard drive. Next step was booting with a Ultimate windows boot disk and run the BIOS exe file to update the BIOS. Restarting the laptop and voila it works again. Just to point out, it's not only the Dell quality shown by the number of BIOS up dates (from A05 to A21) but MS windows xp to 7 is a main culprit as well. This is experience over the last 12 years with different Dell desktops (more then 30 units)

This is the reason that I privately bought for my wife an Toshiba which came with Win7, after half a year it played up  and I installed Opensuse 12.3-64bit since then (over two years) there has been not one problem. Interestingly my wife didn't have any problems with the new system either.

I myself privately throw out  windows many years ago and use on my 2 desktop PC's Opensuse which is running now on 13.1-64 bit .

Conclusion from the text above and my experience, Dell and Linux are a far better combination to a windows  installation.

Harinder, you said you could choose diagnostics. Do the diagnostics run and you can see them run? (You confuse people when you added on "allso boot from Cd still blanck screen after that".)

Even if you can't see the diagnostics results the motherboard diags should run. One of them will display color bars and ask if you saw the color bars and it will be-bleep at you to respond and keep be-bleeping until you do respond. Did you in fact see the color bars? Does it be-bleep at you?

After asking about the color bars to which you should just say Y, after about 5 minutes it should ask if you want to run remaining memory tests. Say N (even if you can't see the question), then it will ask if you want to boot to the diagnostic partition. Even if you can't see this, say Y. (This assumes your hard disk has a diagnostics partition, I'm not sure all of them have one and I'm not sure what happens if you don't have one.)

If you do have a diagnostics partion and your hard drive is working with that partition, you will be given two choices. Even if you can't see anything on the screen, push the down-arrow once and press Enter which selects Test System. Then some drivers will load. Some drivers may actually be for video. Wait a minute or two for the drivers to load. Then push the down-arrow key once which will run Extended Tests. These are interactive so if you still can't see anything you won't be able to do much.

If after all the above you still can't see anything, it may be that the more advanced video driver/chip is bad.

Hi mauro,

Did you ever fix your issue?   This happened to me today,  I can't even get to the bios screen.

Hi Amagi,

Just try a self booting CD/DVD as described in my article (dfwh),  as you may have to update the BIOS.

A simpler way as described, would be using a spare laptop hard drive with a simple XP installation to

update the BIOS. If you can't get a screen display with any method described either the main board or

the screen is faulty.

Cheers

dfwh

I received the attached error. Know of a solution?

thanks for this suggestion

apparently it's one of my USB ports as well, shorting out something

In my case it's the front one on the right side

plug something into it and it boots fine

take it out and the mystery black screen reappears 

Hello

today I experienced the same problem: Black screen at boot up on Dell Latitude 6430u. Windows booting it was ok (I  heard the windows sound at login). Only two times the dislay got back lighting, properly.

I tried many times to witch it on and off, unsuccessfully.

Then, I unmounted the battery and the back cover (refer to Dell Manual documentation statementes, to do it) and I found the Display LVDS cable partially umplugged from its soket. I plugged in the LVDS cable within its soked and the problem seems disappeared.

thi is my experience.

Bye bye

Mario 

Man,

You Rock.

I was aware of a faulty USB port on my e6420 but didn't think of it as the cause of this issue.

Thanks to you it is usable now.

Kind Regards,

Endre

Hello,  i have a Dell Latitude E6420.  When i switch on it boots but i don't see the logo on the screen even after booting. The screen is on but nothing displays. I tried one solution you gave on a previous post( unplug charger and ac supply then press the power button for 20sec. Switch on after plugging the ac supply and hold press the fn ket for diagnostic test to appear)  it produced a beep sound signaling an ongoing diagnostic but nothing displays on the screen. Please whet is the cause and what should i do ? My graphic card software crashed a week ago. Please help me ??

Based on the sympoms my fist guess is a faulty GPU. Is your E6420 a discrete grphics (nVidia) model or oa built-in (Intel) graphics model? If it is a bulit in graphics, than the gpu is in your CPU. You can try another processor with your machine. You can pick up a used i5 for a few dollars.

The discrete graphics is bulit on the motherboard, so I have no ide how to diagnose that. Someone could help. 

Hi to all and sorry to hear that Dell kinda became a lame brand...

My history:

Always wanted a Dell, i have dream about it - a powerful beautiful long lasting piece of tech.

Started to search online a laptop e6420, e6430 something in this area.

One day i find it: e6420 i5 4gb back-light keyboard webcam, all perfect BUT without HDD - 75€ price, i have jumped on the seller, send it an sms and one hour later my dream was in my back sit on my car on the road to home.

The moment i have buy it i have powered on the laptop, entered the BIOS - all was there: the CPU, the RAM all settings available.

Back home i have put it in my desk and let it there few days as i was busy with some home improvements.

2 days ago i have plugged in a 500Gb fully working HDD (with WIN7 installed) and pushed the POWER button.............. after Dell logo screen (i start to hate it actually) the screen goes BLANK, the only thing i see is a cmd type cursor that flicker 2-3 times than NOTHING !!!

Oh boy i said... something smell like cat ***... Going online and first gggl results was this bleeding Dell forum :(( SO my dream was washed away totally, and i have advised ALL my customers or friends to buy a Dell if they want a solid machine :( stoopid move...

Of course i have opened the back cover, powered on and to figure out that the fan is not spinning at all and the pipes became very hot in a matter of 10-20 sec.

Can i have the HUGE luck to replace the fan and the laptop became functional ???

I will totally take it apart and see if the LVDS cable is ok and i don't know.

If i will not be able to find a fast and cheap fix i will spend my time and energy to make people know about the going down dell brand.

I mean boys how the FK could you make a BIOS update (to fix heating problems) and damage the motherboards ???

Yeah you could tell me that's the risk if i have buy it on the street corner... ok but when i see that the exact the same model was fried after 1 year, i congrats myself, at least i have not payed a ton of cash for a under mediocre product...

I'm not saying that all Dell series ***, but for me FIRST contact matters, and for the moment the first contact became the last one.

So sorry to OP if i have posted on the wrong section, anyway i see that the dell geeks don't even bother to answer anymore so another "pink" point for your services...

Hope you all to find the cheap solution and fix your to pricey machines...

Have a not blank dell style day

So "proudly" Dell E6420 owner...

Symptoms:

- can i see Dell Logo on boot with A09 Bios Revision: YES

- can i acces BIOS menus with F12: YES

- can boot from whatever (dvd, usb, hdd): NON - the screen seems alive but blank

- can run diagnostics: NOT SURE as i see nothing on the display

- can hear the beeps when i power on the laptop without RAM, HDD, battery: NON

- when i power on, the fan stars few seconds that stops => pipes and CPU became hot (i can still touch it, is not boilling)

Actions without results:

- swaped RAM

- long press on power button to remove static bshhhit

- pull out/ pull in the LVDS cable on the MB

- tried with a 100% working RAM

- try it with an external monitor on VGA port

- try it another Dell charger

- inspected visually and shaked the USB cables (nothing wrong, nothing short to ground)

- cried on my daughter shoulder (jocking)

- hit it 6420 times with a small 20kg hammer (jocking, but the ideea is there...)

Questions:

- what to further do/try ?

- how could i know if it has a discrete graphic card ?

- what is a better ideea - buy only i5 CPU or a MB ?

Thank you in advance

I will send beer money to the one who will provide THE solution...

Hi Vaishnav_ravi, my problem was absolutely the same. I used to reset the BIOS to boot, but now it doesnt work. After I was able to boot, I tried looking at the MBR and BIOS  boot sector files, changed the MBR a bit, but it still didnt work. I found out that the problem was how the BIOS (Legacy) handled the devices. I cant describe it properly, but the problem was in the BIOS itself. If you dont want to wipe the hard disk/SSD, plug in the hard disk into some computer (Work, school, friend, e.t.c) and backup the files, then I would suggest taking the computer to the nearest Dell Service.

- NoPlayY