Thinkpads Forum

I'm trying to fix my dad's T400. It was an eBay purchase and worked fine for six months, but now it randomly freezes doing general computer activities like browsing the web, Youtube, listening to mp3s, etc...

It does NOT blue screen but instead the screen is normal but there is no response to any keyboard or mouse input. The only way to reboot is hold the power key down and start over.

I have Speccy running in the background, minimized to the tray, to monitor temps and the CPU ranges from 33 to 47 Celsius and the motherboard ranges from 42 to 57 Celsius. Speccy also says the S.M.A.R.T. status of the hard drive is good. I ran MemTest86+ for 45 minutes and no errors with the memory (4GB).

Are there any log files in Windows that can tell me what is causing the freezing up of the computer?

Is there any Lenovo specific software that can help diagnose the problem. What about any non-Lenovo specific software, if better.

Burn a memtest86 CD, boot from the CD, run a long time.

http://www.memtest86.com/

Go into Control Panel/Administrative tools/Event Viewer
That has a list of crashes/errors/warnings/etc.
If you can't figure it out yet, make a note of date/time when your machine freezes next.
Then reboot and go in Event Viewer to look for the matching Event.

Thanks for the tips!

Did a MemTest86 run for seven hours and no errors.

It crashed about 30 minutes ago and I checked the Event Viewer Application/Security/System logs for information at the crash time and there wasn't anything noticeable before or afterwards - just services starting back up after the crash. If the computer doesn't blue screen, would the Event Viewer log the problem? I thought that was for blue screens only?

Any other suggestions? Thanks again everyone.

I think it could be a temperature issue.

Hans Gruber wrote:I think it could be a temperature issue.

Download http://www.cpuid.com/softwares/hwmonitor.html
(it's free)
or your favorite equivalent.

Maybe it needs a complete reset.
Check in BIOS that there are NO passwords set.
Remove battery/charger/HD/CD/RAM and the yellow CMOS battery.
Reconnect the keyboard if removed, then press and hold down the Power button for about 20 seconds.
This does a hard reset to the system.

Measure the voltage of the (CR-2032) CMOS battery: red +, black -.
If it is +3.0V or over, reinsert that battery.
If less than +3.0V, get a new one, such as this: http://www.ebay.com/itm/111672191047
You can reuse the old one until replacement arrives.

Connect only the charger and try to boot.
It should beep 1-3-3-1, indicating there is no RAM.
If so, remove charger, insert RAM, CD and HD, connect only the charger and try to boot.
It should now ask for Date/Time (date is set as MM/DD/YYYY).
Set it, press Esc, then F10 to save/confirm and reboot.
Windows should now start.

With a bit of luck your problems might now be gone.

That reset method looks complicated. I don't think my dad will be able to manage that, but I'll help him the next time I'm in town.

However he was able to install HWMonitor (thanks for the tip), and the temperatures shown by HWMonitor are the same as the program I had previously installed, Speccy. So both programs are reading the same sensors inside the T400.

Now, if it IS a temperature problem, what are potential solutions? With a laptop it's not a simple as installing another fan or large heatsink. Is there any Lenovo fan software to make the T400's fan spin faster? Would a laptop cooling mat help?

If it's heat do this:

1. Download the Hardware Maintenance Manual for his machine

2. Remove the Heatsink and fan

3. Clean the fan and CPU with some rubbing alcohol

4. Apply a fresh coat of Arctic Silver 5 to the CPU. Basically place one drop of the compound roughly the size of a single grain of rice in the middle of the CPU die.

5. Reassemble the laptop.

NOTE: While the laptop is open, this would be a great time to get a can of compressed air and blow out all the dust and gunk from the insides. Also hit the fan and the heatsink fins. Don't let the air spin the fan. Hold the fan still and hit it with the air. Otherwise it will spin the fan way too fast for what it was designed for and could damage it.

Let me know if you need me to clarify anything.

Perhaps obvious, but if heat doesn't seem to be the issue, have you run a virus scan and have you check the hard drive for problems? These should be easy to do remotely. Symptoms you describe could be indicative of either.

Good luck.

Can you post the full SMART data? Some programs don't see some issues as enough to issue a warning.