frozen screen, then dead - a GPU problem? Help

[ryan2000]

I would like to ask for your advices, because my thinkpad has a weird failure.

Please help me to judge whether it's a GPU problem, so I can decide if a reflowing of GPU should be done.

Let me describe behaviors of my thinkpad. A few days ago, my thinkpad suddenly had a frozen screen and I have to use power button to force it reboot. It occasionally has a successful cold boot, but the screen will display shaking image like experiencing electrical disturbances. Soon, the screen will freeze and the laptop die. I replace with a good AC adaptor, but it has the same problem. However, when only the battery is the power source, the thinkpad works fine. So I wonder if reducing CPU speed could help. I set CPU speed in case of using AC power under the power setting to medium, however, it does not help. The thinkpad will still freeze when using AC power.
It looks so weird. Do you think it could be GPU connection problem?

If it is, should I use a moderate procedure of reflowing since my thinkpad just developed its problem and may need less heat to fix GPU connection? Say, a little bit fast procedure of heating, thus the GPU will get less heat in total?

Thanks!

[poshgeordie]

Hi Ryan and welcome to the forums.

I'm not sure what's happening with your TP, and from what you say it doesn't sound like an actual graphics problem, but there are bits of what you describe that could point to that.
Always working on battery's strange though....

First thing I would suggest is to set the bios to the default settings. Boot up and press F1 to enter the bios screen.
Then press F9 for the default settings, and then F10 to save those settings.
This sets the CPU to default settings and should allow you to discount the the CPU settings from causing display problems.

Moving onto testing whether the graphics chip soldering is faulty, power down the TP and remove the keyboard.
The graphics chip is to the front of the aperture under the keyboard, and labelled ATI - removing the ribbon connector to the touchpad helps to get to it.
Press down quite hard on the top of the graphics chip and power the TP up.
Check that you get the display. Stop pressing on the chip and move the TP around. Does the display go off? Then you may well have the graphics problem.

If the chip needs reflowing, then it needs reflowing and there's no such thing as giving a moderate amount of heat to fix it. If you have the problem then some of the ball grid array (BGA) solder pins have become detatched from the motherboard and need to be resoldered; this requires a set amount of heat to resolder the balls back.
Also may I suggest you don't try it yourself since it's very easy to permanently damage the chip / motherboard.
In the States Jamiphar comes highly recommended for doing reballing and reflowing.

Moving onto your TP working on battery, depending on the bios settings, the CPU will be working in a particular mode. This is why I suggested resetting the bios to the default settings.
One thing which comes to mind is whether the CPU is overheating and causing the freezes / shutdowns.
You may want to think about cleaning up the CPU fan and renewing the heatsink compound. Quite easy to do, since you just need to remove the keyboard, and front and rear bezels (see the doc in my signature).

Good luck!

[ryan2000]

Thanks, man!

About the battery, not always works. With a good battery, the laptop still occasionally boots up. But if it successfully boots up with only battery , the system is stable and won't go die. However, it will definitely have a frozen screen in minutes when using an AC adaptor. Weird! Don't know why. The only possibility I can figure out is the CPU speed. As I said in previous post, I reset the CPU speed for using AC power, but it didn't work!

Actually, I've replaced the CPU fan around a year ago. And I also have tried cleaning the fan and the motherboard. But it didn't work.

I'll try resetting the bios as well as pressing the GPU when booting the laptop. I'll keep you updated.

Admin edit: Removed quoted message as it's obvious who/what is being replied to.

[ryan2000]

I reset bios to default, but it didn't work.

When the frozen screen appeared, I pressed the GPU and found it is very hot. It felt not normal. Is the hot GPU the reason of frozen screen? What can be done?