Thinkpads Forum

Specs:
Thinkpad T61 Type 6459-CTO
15.4" Display
nVidia Quadro NVS 140M
Core 2 Duo T8100
4GB DDR2 RAM
Windows 7 64-bit
128GB SSD

This started one day when my power brick went kaput and I had to replace it, though the symptoms came on gradually. But here's the short of it.

The CPU speed will not go higher than 1194 MHz, roughly half the rated speed of the CPU.

It thinks that it's plugged in no matter what. The plug LED will always stay lit even if it's on battery, and Windows thinks it's still plugged in. The screen won't dim or anything.

It won't charge a battery, though Windows thinks it's charging, even if it's not plugged in. I have two batteries, both good. I also have a T60, which charges both without issue.

It will BSOD without exception, eventually, if I run Firefox with hardware acceleration enabled. It gives an "NMI Check/Parity Error" message, or sometimes the monitor will just go black and never come back on. I ran memtest86+ for several hours, no error. And it only does this on Firefox. I can run Portal 2 all day without a hiccup.

It will not respond to the power button at all, and I've tested it with a couple of keyboards. If I shut it down from Windows, it won't power up, which brings me to....

I have to have the BIOS battery out for it to power up. The only way to get it to boot is to unplug it and plug it back in.

Rarely, it will randomly go to sleep for no reason. I can Fn+F4 to bring it back, but it'll go back to sleep almost immediately. This can go on for a few times.

It does not overheat. The fan is clean and the thermal paste is pretty new.

I don't think it's the GPU, even though I've read some horror stories about them. I don't get random colors, or black screen on boot, and I can play games that are much more stressful on it than Firefox without a problem.

C-Man wrote:
I don't think it's the GPU, even though I've read some horror stories about them. I don't get random colors, or black screen on boot, and I can play games that are much more stressful on it than Firefox without a problem.

While it doesn't sound like your run-of-the-mill nVidia GPU problem, it certainly does sound like a motherboard that is on its way out.

You're probably right. I'm wondering if the whole charging circuit got shorted somehow, and hosed something else in the process.

Not sure if this is gravedigging, but it saves the trouble of stating the problem all over again. And somebody might find this interesting.

Anyway, I found the solution. I was about ready to disassemble and part out what I could. When I pulled the battery out, my finger just happened to pop the cover to the docking station port open. And there was a ridiculous amount of corrosion inside of it. The rest of the laptop was perfectly clean, except for the never-used docking port. I took a toothbrush and tried to knock the corrosion out, and the pins pretty much disintegrated on contact.

There was nothing to lose, so I took a screwdriver and broke the plastic out of the port, snipped the remainder of the pins out, and cleaned everything up. Lo and behold, every single issue was solved at once. It'll charge batteries just fine, run at full speed, and I haven't had a single glitch.

And it only took you about a year to find the solution? Congratulations!

EDIT: Nope, not feeding you.

Congrats on finding the problem!