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d_omin · #1 Post by **d_omin** » Mon Nov 23, 2009 4:50 am

Hello again,

Yesterday I had serious failure of my T42. Its just shut down without any warning (go suddenly to black screen) and I couldn`t turn it on (no action on ON button). I removed battery and insert it again and then it starts to work.
What could been the reason of this problem?

Thanks for any advice.

esquire · #2 Post by **esquire** » Mon Nov 23, 2009 5:09 am

Could be overheating, or perhaps the common GPU problem.

poshgeordie · #3 Post by **poshgeordie** » Mon Nov 23, 2009 10:53 am

esquire wrote:Could be overheating, or perhaps the common GPU problem.

+1 on the overheating to start off with. If you leave it for a while does it turn on again?

If yes, then it's quite simple to strip it down to remove the fan and clean it out etc. Have a look at this strip down document. Strip down as far as (and including) the keyboard bezel. Also remove the System board screw in Section 4.

Remove the three screws holding the fan assembly in place. Disconnect the fan connector as you lift the fan off the motherboard.

Clean all the dust etc from the fan and assembly. Before replacing the fan again, clean off the old heatsink compound and replace with a very very thin layer of new Arctic Silver heatsink compound.

If there's still no sign of life when the laptop's cooled down check the following in this order:

1. Memory modules are correctly fitted. IF you do get it working I'd suggest checking the memory's OK. Download and burn a bootable CD with memtest86 and run at least three full cycles. Iso Recorder 2 is a simple on click CD iso burning program.

2. Remove all the daughter boards, CD and HDD's, main battery etc so there are no periferals connected to the motherboard. Connect the keyboard and see if it will fire up from the AC adapter. If it does connect each part in turn to find out which causes the laptop to not start up.

3. Try another keyboard (if you have one) in case your one has a faulty on off button.

4. Check the fuses with a multimeter - this document showing the T4x fuse locations will help.

Other's will also have suggestions as well I'm sure.

Good luck!

d_omin · #4 Post by **d_omin** » Mon Nov 23, 2009 4:04 pm

It has happened once yet so it`s difficult to tell something else. But I will observe temperature and other parameters. Today I noticed that there is some problem with battery, normally it runs for about 1h 40", now it`s discharging very fast (in about an hour). Battery is very old (4 y.o.) capacity ~26Wh (designed 45Wh) may be it`s it?

poshgeordie · #5 Post by **poshgeordie** » Mon Nov 23, 2009 4:20 pm

If you are running on battery only and it runs down to less than 10% approximately, there will be a number of warning messages telling you to either attach the mains AC adaptor or to turn off the laptop.

If you don't do either of these things, the laptop will eventually turn off by itself.

Also the batteries don't last very long and it does look like your one is starting to fail.

d_omin · #6 Post by **d_omin** » Mon Nov 23, 2009 4:51 pm

Yes, I set the low battery alarm at 12 % and the critical alarm and go to hibernation on 8 %. I noticed that sometimes my T42 goes to hibernation earlier than the battery achieved level of 8%. Now I reconditioning battery and will see what happen, how long does it (battery reconditioning) take normally? What level on battery health saver should I set up (stop charge, start charge)?

d_omin · #7 Post by **d_omin** » Fri Nov 27, 2009 2:51 am

I happened again today, suddenly it turned off and I have to remove battery to turn it on. I noticed that in both cases I plug/unplug USB device or do something near the USB ports. What could be reason of this issue?

poshgeordie · #8 Post by **poshgeordie** » Fri Nov 27, 2009 5:16 am

The first thing you must do is to check the fan is clean and not blocked with dust and dirt - see my first post about how to do this.

d_omin · #9 Post by **d_omin** » Fri Nov 27, 2009 7:01 am

Yes I will do it, but I read some posts about "T42 USB issue" the common problem in old thinkpad. (e.g. here http://forums.lenovo.com/t5/T61-and-pri ... /m-p/68146 or here http://www.flyertalk.com/forum/travel-t ... -cord.html) When You plug/unplug USB device (e.g. pen drive) computer shoutdown without any warning and it`s not possible to turn it on without battery replacing. Some time it bricks the computer forever. Does anyone hear about it ?

#10 Post by **RealBlackStuff** » Fri Nov 27, 2009 8:00 am

Read the 'stickies' at the top of this forum:
t40 doesn't recognize usb ports
and
t42 shuts down when i move it:

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