I bought my Thinkpad T23 laptop second hand on eBay, and I have to say Thinkpads are, by far, my favorite laptop: rugged, mechanically well-built, and reliable, but it seems the T-series suffers from what many people say is a design flaw.
Anyway, I was using my Thinkpad until it started intermittedly locking up. And I mean *really* locking up. Once this occurs, the laptop cannot be turned off, even by holding the button down for X number of seconds. You had to unplug the laptop, flip it over, and yank out the battery to turn it off. With time these lockups became more frequent, and to make matters worse, sometimes it would not turn on again. This got progressively worse until the laptop refused to ever turn on, effectively becoming a rather rugged paperweight.
By not turn on again, I mean the computer does not pass POST, it turns on, the fan speed pulses (from high speed to low speed), the screen stays blank, and the computer remains unresponsive. Removing everything, even the RAM, did not fix it. To show the scale of the problem, when you remove all the RAM from a Thinkpad and turn it on, it starts beeping to tell you there is a RAM error. This computer did not even register the fact it had no RAM (no beeps).
This led me to believe that this was a major issue with the BIOS, possibly a BIOS failure. This had occurred to me once, with my first laptop, an IPC Archtec, which failed in exactly the same way (intermittent lockups, then refusal to boot with fan pulsing). The result of that was that I binned the laptop, and used a Dell Inspiron (until I got the Dell Latitude). Seeing exactly the same issues with my Thinkpad, and the fact I did not have a warranty, got me worried that it was destined to the same fate.
Unlike the IPC Archtec, the Thinkpad has a great information network. While finding virtually no help/support for the IPC Archtec (I only found the official forum, and the fact that all my posts, and other peoples posts about hardware failures, were being removed as fast as they were being posted, lead me to believe that IPC was more interested in covering up any problems then helping fix them) the Thinkpad has a dedicated set of followers and information (not to mention free service manuals, thanks IBM!).
The Thinkwiki forums helped me immensely when picking which Thinkpad to buy, while also showing me all the possible add-ons that can be purchased (and providing things like what battery model is needed for which laptop, a godsend when buying batteries over eBay). Highly recommended when looking at what Thinkpad to buy.
But my saviour in this case is the Thinkpad forums, more specifically, this post, where it talks about the issues that I have been experiencing, and point out what the problem may well be.
Looking at the pictures on the forum, and from what was posted, it seemed that the problem was due to an induction coil getting disconnected from the motherboard due to excessive flexing of the board. It seemed that all you had to do was to resolder the inductor and the problem would be fixed.
Being a poor student, and the fact that since my Latitude was stolen (and I didn't get any insurance), what little money I had left went into buying the Thinkpad. Spending money on a new motherboard for my Thinkpad is beyond my budget currently, so I decided to see if I could repair the board.
First thing you have to do is to get through to the mainboard. This is no easy feat, requiring the removal of almost all the parts of the computer before you get to it.
For the dissasembly itself, follow the IBM service manual, it is by far the best resource you have for properly taking apart your Thinkpad. You need to remove the "System board" as shown on page 119. You can find the manual here.
Once done, you should have something like this:
This is the Thinkpad motherboard, removed from the rest of the case. The area that contains the part we are looking for is highlighted in red. Below you see a zoomed-in version:
Sure enough, the contact on one of the inductor coils had been broken. The picture below shows the broken contact of the coil:
Now soldering the component back on proved tricky. My soldering iron kept touching other components, weakening their bonds to the PCB. So I had to think of another way to solder this. What I came up with involved the soldering iron not having to go near the other components at all.
First thing I did was to bend the component further out, as shown below:
Then place a blob of solder onto the spot where the component meets the pcb, make sure it melts and spread across the entire contact. Then place a blob of solder onto the connector's pin. Once this is done, push (I used a screwdriver) the component against the PCB, and apply heat to the pin. Due to conduction, the heating of the pin will cause the solder to melt and move downwards due to gravity, the blob on the PCB will also melt, and when the two meet, pull the soldering iron away and keep pressing down until it cools. For me this provided the best way for soldering the component back on.
Once it has cooled, you are done. I recommend you test the connection with a continuity tester, to see if there is a good connection (you don't want to put it all back together, just to find out you didn't solder it properly). The two red highlights on the picture shows where I successfully tested the continuity. These points should work for you as well (unless there are some differences in the T-series motherboard layouts).
Test proved ok, put it all back together, plugged it in, and it boots!!! It actually works! Believe it or not, but I wasn't so sure this would fix it, I thought the problem would be far more complicated. From me writing this, the computer has been on 2 days solid, and it's as good as new.
It has had quite heavy use so far, I wrote this article on the T23, and there have been no lockups at all, the Linux "uptime" command puts it at 2 days, 4:50 with 12 users and a CPU load average of 3. Even with all this load, there has not been a single hiccup so far, which is promising.
My only regret after doing this is the fact I binned the IPC. Chances are that it was the same little fault, and I would have had an extra laptop (which i could sell, or turn into a tablet as a project). Oh well, now I know what to look for if I come across a laptop which has these symptoms, and you too if you read this page.
Reasons abound, the most likely reason is the switch to lead-free solder, coupled with its proximity to an area of structural weakness. The forum linked before has a little debate on it.
The laptop is still going strong years after the fix, which is great. I had just bought another T23 laptop which was faulty, with the same problem. I fixed that motherboard as well, and then merged the two laptops, resulting in a machine with a 1.13GHz PIII and 1024MB ram, which is likely to satisfy my needs for time to come.
It seems that a lot of laptops which are faulty (read: being sold cheap) in fact just have this issue, so there are a lot of bargains to be had out there! :)