Advice a good HW forum to ask for a LCD laptop problem

[cettolox]

Hi,

I have a classical "flickering" display problem on my Dell C840 laptop. Since I cannot understand if the problem is relate to the lcd or to the inverter or to che graphic adapter, maybe someone of you knows a good HW forum to ask for a suggestion (I know this is a SW forum, but all you people are so good in any computer stuff..).

Anyway I also tell you the symtoms, in case there is some advice here.

- the lcd flickers and shows random patterns
- it gets worse as time goes by (if the pc is cold it happens after 20mins, if it's warm it happens immediatley)
- it gets worse or better if I twist the base unit
- it gets worse or better if I lightly push or pull the lcd (see here http://www.youtube.com/v/AbHDsUnY5PA )
- as the patterns on the screen get worse, at a certain point WinXP freezes and reboots
- I get the same problem if I connect an external monitor
- I get the same problem if I connect to the laptop via VNC or LOGMEIN (remote desktop). (I think this excludes the lcd and inverter, since it means that the corrupted patterns are sent via tcp/ip to a remote controlling machine....
- I tried with no success to change operating system, to work disconnecting all the disconnectable hardware, to change RAM dimms, even to change the whole motherboard

I suspect a video card fault (I think onboard video memory broken).

Thanks,

/Stefano

[tomos]

I cant personally recommend any but have you had a look at the dc links page ?
https://www.donationcoder.com/Links/

Best Help / Tech Support Tech Support Guy Forums Excellent forums dedicated to helping people with all hardware/software problems. Suggest A Fix Free Online Tech Support Forum.

[tomos]

or from "Best Forums for.." thread

Hmmm....There are several forums I'd like to recommend.
1) For questions about computers (hardware and software), the Internet, and related matters, I love the Neat Net Tricks forum at http://www.topfreefo...mforum=neatnettricks.  The expertise of the participants ranges from newbie to awesome, and I've found the atmosphere very friendly and helpful.  (I also like their multi-reviewer software reviews: http://www.neatnettr...reReviews/splash.htm)

-cyberdiva (February 08, 2008, 05:09 PM)

[Carol Haynes]

Haven't you answered your own question? If it happens on external monitors it is unlikely to be the built in LCD or its associated components. It sounds more like a graphics adapter chip fault. The fact that it gets worse the longer the system is on is a classic chip problem - it is failing because it is getting hot and doesn't like the heat - that's why it occurs when you reboot or switch off and on without giving time for it to cool, and also it would account for Windows freezing.

I see the laptop has a separate graphics card - is it possible to find a replacement (or a loan from someone who has the same laptop?) to check out if it is the graphics adapter.

The online service manual for this graphic adapter is at http://support.dell....sm/vidbd.htm#1102650

Have you taken the system apart before this problem? If so note the last comment in the above document about intermittent graphic card failures. Check it is properly seated (remove it and reinstall it checking there is no dust around the connectors and that the flex cable is reseated properly).

If you do need a graphics card see

http://accessories.u...2&chassisid=8480

there is a contact number, but you may need to look for a working second hand card as all Dell seem to stock are the screws to secure the card!


Extra note ... just checked there are some of these graphics cards on eBay but they aren't cheap - is it time for a new laptop?

[cettolox]

Haven't you answered your own question? If it happens on external monitors it is unlikely to be the built in LCD or its associated components

Yes, but since I already purchased a motherboard without solving the issue I wanted to be sure that, buying a video card, I am going to solve it (I cannot loan it, already tried).

Have you taken the system apart before this problem? If so note the last comment in the above document about intermittent graphic card failures. Check it is properly seated (remove it and reinstall it checking there is no dust around the connectors and that the flex cable is reseated properly).

I removed it and reinstalled it several times, cleaning everything. So it is not dust related.

is it time for a new laptop?

:-) Yes, probably, but the fact is that the C840 has been an excellent laptop... repairing it with a new video card (quoted arount 50$ on ebay) was I think a good thing to do.

Thanks,

/Stefano

[cettolox]

Update. Changed the video card, 40€ on ebay, solved the issues.

Thanks everyone,

/Stefano

[f0dder]

Changed the video card in a laptop? That sounds like pretty delicate surgery - glad that your problem is solved, though.

[cettolox]

It's easier to do than to explain... the reason is that the card is not integrated: so I had just to disconnect the keyboard, diconnect the lcd cable, unplug the old card and to assemble back. The harder part was the diagnosys.

Bye!

/Stefano

[Carol Haynes]

Glad to see you got it fixed