# Dell laptop display blank



## kingjim103 (Feb 28, 2011)

I have a Dell Inspiron 1720 laptop, which has been working 100% fine until yesterday. It was in standby with the lid shut, I opened the lid and the screen turned on (as normal), I then closed the lid (settings dictate that it should have remained on, only turning the display off). When I opened the lid a few minutes later, the display would not turn on.

I restarted several times, the computer seems to boot up, i.e. the fan comes on, the battery/power lights come on, yet the screen remains blank. I have tried attaching an external display (via VGA) but this did not turn on either, so I believe the display itself is not the problem. I have also checked the connection to the display and this seems ok.

I have tried removing the battery and power cable and holding the power button down for 30 seconds without success. So, it seems that most of the components are working, but the laptop is not communicating with either the internal or external display.

Any ideas as to what may be at fault, or how I could further troubleshoot?
Also, it is 3 years old, out of warranty, and had a new HDD and RAM last year.

Thanks in advance,
James

Dell Inspiron 1720
Windows 7 (64bit)
nVidia GeForce Go 8600M GT
Intel Core 2 Duo Processor T7500
Western Digital 320GB 7200RPM SATA 3GB/sec 16MB Internal Hard Drive
4GB RAM


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## makinu1der2 (Jan 1, 2008)

Take a look at the thread below and complete as many of the steps as possible.

Try removing the RAM and test the modules individually.

http://www.techsupportforum.com/forums/f108/black-screen-issues-and-troubleshooting-498132.html


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## kingjim103 (Feb 28, 2011)

Thanks for your reply. I have tried to go through as many of the steps suggested in that thread. I have taken the laptop apart, removed any dust from the cooking fan. I then removed and reseated both RAM modules, did a hard reset and restarted. No luck. I also tried every combination of RAM modules but again, nothing worked. I also reseated the HDD aswell as trying to start it without the HDD in. I also removed the CMOS battery without any improvements (although it did beep twice when i turned it on). So, it seems the problem isn't the HDD or the RAM or the BIOS. 

So far, there's been no improvement. It still starts up and both the HDD and the CD make noises, the volume buttos work, and caps lock/num lock lights work and respond to key inputs. But the screen is still black and an external display won't work. 

As for repeating the CPU and GPU, i don't feel confident enough to attempt this so i can't confirm that they are not problematic. I am wondering if anyone has found a solution to this problem? Could it be something much more simple such as the switch that tells the computer whether the lid is closed is faulty? And does anyone know how to fix this?

Thanks again for your help. Any further suggestions would be very much appreciated! I really want to find a way to fix this as i can't before a new laptop right now!


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## tim19889 (Jan 24, 2010)

Have you tried looking at the connections between the internal video card and your laptop's screen? Not sure if you would be able to access that or not with your particular laptop, but it's worth a shot. If when you boot up the computer the fans are running and it sounds like Windows is loading, but you just don't see anything, then it sounds like it might be a loose connection somewhere, or something's physically wrong with your video card or laptop screen. Since you say you tried connecting to an external display though with no success, I'd assume it's something wrong with the video card or the connection between the video card and internal or external display it's trying to connect to.


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## makinu1der2 (Jan 1, 2008)

When connected to the external monitor did you toggle the display? (Press <Fn><F8>)


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## kingjim103 (Feb 28, 2011)

I did toggle the display when the external monitor was connected but nothing happened. The video card is integrated into the motherboard so im not sure how easy it'll be to access. I have checked the connections between the wires that go to the display and from the main part of the laptop (ie. the cables that pass through the hinge of the laptop). Does anyone know how i could check the connection where the display/VGA leave the Graphics card/motherboard? 
Thanks for your help


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## makinu1der2 (Jan 1, 2008)

If your not getting any display to an external monitor or the LCD screen 

then the issue is usually related to the graphics chip or the MB.

You can find the Service Guide below.
*
Inspiron 1720 Service Guide*


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## kingjim103 (Feb 28, 2011)

Ok thanks for your help. I'll have a look at that tomorrow when i've got access to a computer. Another thing i've just realised is there's no windows booting sound so maybe its not booting as successfully as i first thought. The HDD is definately working tho. I'm thinking this is looking more and more like the motherboard's gone! Does anyone know if there's a way to find out if its booting properly without any display?! Thanks


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## tim19889 (Jan 24, 2010)

I've never done it before but you would need to buy a POST(power on self-test) card, plug it into your machine, and it would tell you exactly what's happening when you boot and where it stalls at. 

I don't think your MB is shot. If it was nothing would happen when you try to power on your laptop (no fans spinning, hdd would not spin, etc.). What's more likely is that your graphics chip or card on the MB is faulty, or else a loose connection as I've said. Good luck trying to find that stuff tho, I'm no help to you there I know nothing of how dell laptops are set up lol.


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## kingjim103 (Feb 28, 2011)

Update on the laptop situation: I took it to my university's free computing repair service so they could take a look. They returned it to me today, stating that that motherboard is faulty and needs replacement/repair. Since this is something they cannot repair, they advised I contact Dell. I don't plan to do this as I am sure tehy'll overcharge me for any repairs. Does anyone know how easy a motherboard replacement/repair would be to do myself? and any costs involved?
Or would I be better off looking for a new laptop? 
Thanks


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## joeten (Dec 4, 2008)

Hi the service manual would be the best guide, it may also have a parts number for the mobo which you can google and see if it is a practical option to replace it, or cheaper to look at a new machine


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## kingjim103 (Feb 28, 2011)

Ive done a bit of research into the cost of a motherboard replacement and it looks like its gonna be a bit too expensive! Time for a new computer i think, planning to go down the desktop route.
Thanks for all your help. 
One final thing, what do I do with the dell lappy? I'm pretty sure its parts must be worth something?! Anyone have much experience of this? I am unsure whether I should put the whole laptop up on ebay, or to dismantle it and try to sell the parts seperately. The display is a 17" 1900x1200 WUXGA in perfect condition, so I would have thought its worth something.
Thanks


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## joeten (Dec 4, 2008)

Hi you could sell parts but not the mobo that would be a no no


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