troubleshooting dell laptop graphics problem

[thejudge0081]

I have been talking to Dell tech support for 3 months, since I purchased a Precision M4800 in November. They have since replaced the motherboard 3 times, the graphics card once, and wiped the hard drive 3 times. With the problems still not solved, they replaced the system. But...

On the new computer, there are blinking horizontal lines and artifacts that pop randomly on the screen. They are not present during pre-boot or in BIOS. It is worst in the Windows standby screens (ex: "press control + alt + delete to unlock...)

I have tried the following:
-update BIOS - no change
-check Dell site for drivers - no change
-run Dell site 40 min diagnosis - no problems detected
-run LCD built-in self test - flickering not present
-run the pre-boot system assessment - no problems detected
- tilt the monitor to see if that has any effect - no effect
- reinstall the integrated intel graphics driver - no effect

-finally, and most interestingly, I temporarily disabled switchable graphics in BIOS, just for grins. On the first boot, there was a brief blue screen, and then the log-in screen. the flickering was gone. I rebooted, and the blue screen did not reappear. Still, no flickering.

I think Dell has no idea. They suggested prior to my switchable graphics check that either the Nividia GPU was bad, or it's driver was. I have downloaded the latest Nividia driver and the Guru3d uninstall tool and have that ready to go, but after months of failures, I hesitated to attempt that. After the switchable graphics test, they said "this no longer points to driver or hardware", without saying what they thought it does point to.

Dell Precision M4800
Windows 8.1
Nividia K1100M GPU
Intel 4600 Graphics Card

I've got pretty low confidence in Dell technical support at this point. Any ideas? Thank you in advance!!

 

[jimmysmitty]

If the switchable graphics are still on then it should be, on the desktop, running on the integrated Intel GPU not the nVidia GPU. So changing drivers or the part won't matter.

Have you run a more in depth memory test such as Memtest 86+? The Intel GPU uses system memory for its VRAM.

 

[thejudge0081]

If the switchable graphics are still on then it should be, on the desktop, running on the integrated Intel GPU not the nVidia GPU. So changing drivers or the part won't matter.

Have you run a more in depth memory test such as Memtest 86+? The Intel GPU uses system memory for its VRAM.

That's how I understood switchable graphics to work as well, so I was surprised that disabling it helped. Do you know why that would be? Is it just using the Nividia with the switchable graphics disabled?

Not yet on the memory test. I'll try that right now.

 

[jimmysmitty]

If you disable the switchable graphics it should default to the discrete GPU, the nVidia. If it is not present when the iGPU is disabled then it is either a faulty iGPU or faulty RAM. I highly doubt the iGPU is faulty as that is part of the CPU itself and those are very rarely bad. I would lean towards bad memory, which I am surprised they didn't try to replace already.

Then again recently I had to deal with Dells tech support. They replaced a motherboard and PERC card in a server then a SAS cable. Still had an error on the iDRAC. I had to explain to them that the error was related to a power port on the backplane but they wanted to replace the PERC card again. They mostly read from a script then just go with the flow. It is easier to replace the motherboard than to do real diagnostics (not their onboard crap).

 

[thejudge0081]

In this case, if they had bothered to push the power button before shipping the computer out, they would have seen the problem on the very first windows screen - the one that asks you what language / time zone.

 

[thejudge0081]

Have you run a more in depth memory test such as Memtest 86+? The Intel GPU uses system memory for its VRAM.

Follow up: I'm 6 hrs into the free version of Memtest 86. Based on its progress I'd guesstimate another 12 hrs to go. I've got 32 gb, and it's on pass 2 of 4. No errors this far. Is all of this reasonable?

 

[thejudge0081]

Update - 14 hours into the test, nearing the end of pass #3. No errors. If the ram tests continue to find no errors, it may be fun trying to convince Dell that it's the iGPU. I think Dell thought I was going to go away last night when I told them the problem was gone after disabling switchable graphics. I couldn't believe I had to tell them that was for diagnosis only and not viable for a long term solution.

Now I've just noticed above where you suggested Memtest86+. I didn't realize until last night that the + indicates a different program. I'm running Memtest86. I tried to research the differences, but I'm still ignorant as to what those are.

 

[jimmysmitty]

I have used both. Memtest86 still gets updated regularly while 86+ gets updated once in a while.

86+ is light weight and is just the tests. There is no limit to the tests, once you start it you can let it keep going and going. And every pass the test gets more complex so each pass takes longer, so if the first pass takes 4 hours the next pass will take 6 hours and so on and so forth.

86 is a bit more advanced, you can set a number or unlimited and you can select which tests to run along with a performance benchmark.

If the memory does pass then Dell would need to probably swap the CPU. That is the only other thing I can think of if they already swapped the motherboard.

Or do the proper thing and just send you a new laptop to swap your HDD into.

 

[thejudge0081]

Unfortunately, this IS a replacement laptop. There were 3 motherboard replacements on the first system. I'm 90% sure the newest motherboard on the system I sent back was bad too. I have been assured that this has escalated for a senior technical tech. Yippee...

This saga is now 3 months old. I have yet to have a functioning laptop, and it's so frustrating. Dell Precisions aren't cheap. I haven't asked for a refund yet, partly because I like the system in theory, I have a 5 year warranty and like the ability to swap my personal and work computers on a dock at home, and I know I would be in for a massive battle if I start saying "refund". Regardless of how much longer I own it, this will be my last Dell. The "buy a Mac" and the "buy a custom" crowds are slowly winning me over.

 

[jimmysmitty]

We use Dells at work because compared to HP they are much better.

If I had a choice though I would probably buy Asus laptops. When I did repairs I had Asus in for the least amount of problems compared to Dells/HPs.

I hope they figure it out. Honestly there is not much else it could be then if they have swapped the entire laptop.

 

[thejudge0081]

I agree. I think we have narrowed diagnosis down as far as we can go.

All 4 of the motherboards I have had so far have had different problems. The first simply melted down. The second would not interface with the dock completely. The third wouldn't recognize the discrete GPU. The 4th, the one in the new system... well you already know.

 

[thejudge0081]

Then again, I still don't understand why everything works fine on an external monitor...

 

[jimmysmitty]

Depends on how the external monitor is being output to. If it is being output using the discrete GPU and not the iGPU then it would be the same reason.

I doubt it is a faulty monitor as the connection from the iGPU and dGPU are the same.

 

[thejudge0081]

Interesting - the monitor is a NEC spectraview ii wide gamut monitor, connected to the dell dock with a DVI cable. I wonder if it uses the discrete GPU because 1- it's docked with AC power, and/or 2- the monitor is a bit advanced for the iGPU.

Dell is currently suggesting they think it's a known issue with switchable graphics in BIOS. I just updated BIOS from A15 to A16 with no effect.

 

[jimmysmitty]

You would be surprised what the iGPUs can handle these days. Most Intel iGPUs can handle 4K 60Hz via DVI, DP or HDMI as well as a lot of ranges.

Still if it is docked it might be pulling from the dGPU instead of the iGPU. Try pulling the laptop from the dock and connecting it directly to the monitor with the switchable graphics turned on. If the NEC monitor presents the problem then we can say for sure the iGPU might be faulty.

 

[thejudge0081]

OK, to wrap this up:
A senior analyst in their resolution group contacted me last night. With my symptoms and troubleshooting, he thought it was the iGPU, without me first saying that's what I thought. Regardless, his plan is to send me another replacement computer. After 3 months, they want me to go away. Replacing my computer is a good strategy. It will be tricky to configure it since the M4800 was discontinued shortly after I bought it and replaced with the 7510, and there are major differences.

Thank you for your help. For folks that see this thread in the future, I am marking your comment above where you thought it was either RAM or the iGPU as the solution.

If you are reading this, experiencing similar problems, we reached the conclusion that the iGPU was bad through differential diagnosis. We didn't have a chance to test it and reach a positive diagnosis. When Dell offered to replace the computer, I stopped digging.