Let's see... I owned a T20, T23, X30, T41p, T43, T60, T60p, and a friend owned a T600e, T42, X60, X201, X220 and now X230. Of all these machines that were never abused, here are the problems:
T20 - just stopped powering up one day, when it was about 5 years old, never figured out why because by then it was not worth repairing.
X30 - LCD stopped working when the laptop was 3 years old, same as above
T41p - Ethernet flaked out, turns out the chip had desoldered and the only fixes were reflowing or new motherboard. Kept using WiFi instead
T60p - USB ports on the right side refused to work with a mouse. Lenovo provided new motherboard, two new USB daughter cards. Turns out it was either incredible bad luck with replacement parts or a design defect.
X220 - IPS screen ghosting issue
X230 - Random reboots, traced it back to the motherboard.
Yes, all the above are anecdotes, but what I am trying to say is that Thinkpads DO die or have defects. Even IBM built Thinkpads, not just Lenovo build Thinkpads. They used to be great laptops with amazing build quality in terms of fit, finish and especially keyboards. What truly set them apart, and this still holds true for HP and Lenovo business class laptops was the level of support. Every problem I had with them during the 3 year warranty period was fixed ASAP.
I still have a spare bag of screws IBM sent me when I swapped the motherboard in the T60p because their service manual specifies replacing the screws when replacing the motherboard.
All that said, I stopped buying Thinkpads with the T60p. The T61p had the infamous Nvidia G84 chip that would fall the fuck off, so I stayed away, and I moved to other manufacturers. I realized I can get better performance for the same price from Acer, Asus or especially Sager. The downside is a complete lack of support, but when you are saving hundreds of dollars on a similar machine it evens out in the end. And this is where laptop manufacturers except Apple miss out. They cannot build a high quality materials, excellent support but expensive machine when they are competing with cheap materials, little support but inexpensive machine.
I still remember fondly most of my Thinkpads, but I'm not going to give up my disposable Acer I am typing this on. It has an SB i5, GT540m, 8Gb RAM, 160Gb SSD that I picked up for $300. And it will SMOKE that brand new Thinkpad advertised in TFA in games.