Jump to content


 


Register a free account to unlock additional features at BleepingComputer.com
Welcome to BleepingComputer, a free community where people like yourself come together to discuss and learn how to use their computers. Using the site is easy and fun. As a guest, you can browse and view the various discussions in the forums, but can not create a new topic or reply to an existing one unless you are logged in. Other benefits of registering an account are subscribing to topics and forums, creating a blog, and having no ads shown anywhere on the site.


Click here to Register a free account now! or read our Welcome Guide to learn how to use this site.

Photo

What does a laptop video chip do?


  • Please log in to reply
4 replies to this topic

#1 Cataria

Cataria

  • Members
  • 25 posts
  • OFFLINE
  •  
  • Gender:Female
  • Local time:07:15 AM

Posted 08 May 2012 - 03:26 AM

This is something I've been wondering, and I'm asking to satisfy my own curiosity; I'm not very knowledgeable when it comes to graphics hardware.

Long story short, the video chip died in my old laptop. Several times, actually -- apparently HP dv9000t's are prone to overheating the video chip, and I had to keep replacing the motherboard until I gave up and got a new laptop. However, every time the video chip died, I was still able to start my computer as long as I disabled the video chip's drivers (NVIDIA), but the results were that the screen had a crappy resolution, a very restricted color palette, and most annoying, lines of various colors flashing across the screen in a seizure-inducing sort of way.

My question is, why could I see any video output at all if the video chip died? Is the video chip still partially functioning, or is there some other (less powerful) video device that it is falling back on? Not sure how that works.

I'm especially curious if there might be a way I could still use the computer in crappy-palette-screen resolution mode, but without the flashy lines everywhere. I could almost still use the thing if looking at the screen didn't make me physically sick.

Thanks for any information you guys can give me!

BC AdBot (Login to Remove)

 


#2 Platypus

Platypus

  • Global Moderator
  • 15,220 posts
  • OFFLINE
  •  
  • Gender:Male
  • Location:Australia
  • Local time:11:15 PM

Posted 08 May 2012 - 04:47 AM

Several HP models had problems generally due to a flaw in the implementation of the nVidia GPU (Graphics Processing Unit). There were recalls, but not here in Australia, so I'm being careful with mine.

What happens varies depending on what part actually fails. A common failure mode is for the solder connecting the graphics chip to the mainboard tracks to fracture. The chip is a BGA (Ball Grid Array) package which has all the connections underneath, so they are not accessible. Sometimes these connections can be "re-flowed" by heating to a carefully controlled temperature, as was done in the original assembly process.

Success can't be guaranteed however, and sometimes the chip has suffered an internal electrical failure. In this situation, because the chips disable unused sections to save power, and these sections will have suffered less thermal stress, sometimes the primary adapter that drives the internal screen fails, but an external screen works OK.

Even if the display will still produce something in fall-back VGA mode, the flashing lines etc probably indicate that the soldering under the chip is in a bad way.
Top 5 things that never get done:

1.

#3 Cataria

Cataria
  • Topic Starter

  • Members
  • 25 posts
  • OFFLINE
  •  
  • Gender:Female
  • Local time:07:15 AM

Posted 08 May 2012 - 07:38 AM

Yeah, my model was recalled, but unfortunately, it wasn't in the range of serial numbers that they were willing to fix.

Thanks for the info! Question though -- when it is running in VGA mode, what is allowing it to do so? Is it still the video chip, in a partially working state?

#4 Platypus

Platypus

  • Global Moderator
  • 15,220 posts
  • OFFLINE
  •  
  • Gender:Male
  • Location:Australia
  • Local time:11:15 PM

Posted 08 May 2012 - 08:25 AM

when it is running in VGA mode, what is allowing it to do so? Is it still the video chip, in a partially working state?

In the units with the nVidia GPU, yes. All the video functions are handled by the one chip, and fault symptoms can range from just some lines or flickers (but tending to deteriorate) through partial function like you describe, to complete video failure.
Top 5 things that never get done:

1.

#5 dpunisher

dpunisher

  • BC Advisor
  • 2,234 posts
  • OFFLINE
  •  
  • Gender:Male
  • Location:South TX
  • Local time:07:15 AM

Posted 08 May 2012 - 09:22 AM

Full story:
http://www.theinquirer.net/inquirer/news/1004378/why-nvidia-chips-defective

I have done so many of these. Long story short the substrate and solder are incompatable and after so many heat cycles the solder breaks/fractures and causes problems. I have had decent luck using a heat gun to reheat/refloat the video chip on videocards and motherboards that NVidia/OEM would not cover. I had a lot of DV9OOOT series covered by HP without complaint. HP was by far the easiest OEM to work with on this problem (unlike Dell).

I am a retired Ford tech. Next to Fords, any computer is a piece of cake. (The cake, its not a lie)

3770K @4.5, Corsair H100, GTX780, 16gig Samsung, Obsidian 700 (yes there is a 700)





0 user(s) are reading this topic

0 members, 0 guests, 0 anonymous users