ThinkPad T400 fan error error report: an example of solving non fan problem

Many ThinkPad players have encountered fan error when starting up, the common situation is fan dust accumulation or bearing oil dry fan start-up difficulties caused by the error, the solution to this kind of fault is very simple, remove the fan dust or refueling. There are two cases we are not willing to encounter, because the word means to spend money, one is fan scrap, one is the motherboard fault, these two kinds of failure to solve up to say simple, fan leaf replacement or repair, according to the situation around to spend dozens to hundreds of oceans is necessary. My T400 is very unfortunate also medium recruit, and still want to spend money that kind, fortunately did not spend money, changed an insurance to solve a problem only, write out to give everybody a reference now, it is a solution train of thought to the machine friend with strong ability to begin, perhaps really encountered the same situation to be able to save a lot of ocean.

Let me start with my specific situation. One night when I was playing games, I suddenly cut off the power and turned it off. Then Fan Error reported that it was very hot at the bottom of the machine. I searched for Fan Error solutions online and found that most of them mentioned dust accumulation or dry oil, so I took apart the dust collection. However, when we take apart the fan, we can only see some dust spots sticking to the surface. It is also very smooth to gently blow the air, thus eliminating the problem of dust accumulation or oil drying. Since you’ve ruled out the easiest solution, plan for the cost — a broken fan, or a broken motherboard. So he contacted a local shop selling new and original fans online. He took the machine to the shop to try out the fans. After several attempts, the shop owner thought the fan he bought was defective, because he said he had not tested when he bought it. After testing all ten of the fans at his counter, none of them worked. had to be found dead on the motherboard.

Later, I thought someone in the altar had sent the circuit diagram of T400, so I downloaded it to see if I could solve it. Open the circuit diagram and find the FAN CONNECTOR page. It has an insurance F4,2.0A. Pump out the machine to take down the C shell U-frame, under the keyboard with A4 paper size magazine pad to prevent short circuit on the boot, and then boot with a multimeter to measure the voltage of each pin fan base, found almost no voltage, more suspected that the safety was broken. However, no F4 insurance was found near the fan socket. It seems that on the other side, had to be disassembled and removed from the motherboard. Refer to the dismantler manual for the specific dismantler process. Since no dismantler process was taken at that time, only the motherboard photos were kept.

I took off the main board and looked at the position of the fan socket on the back, and found F4 insurance. I measured it with a multimeter and it broke. Luckily, it was . I found a replacement card from another used board, installed it, and prayed before starting the machine. I pressed the power switch. After the logo was turned on for a short time, no error was reported, and the long-lost whirring of the fan started up again.

The T400 fan circuit diagram and F4 insurance location diagram of the motherboard are attached below, hoping to provide a reference for those who encounter the same situation. Of course, I hope that everyone will not encounter the best , because if encountered, at least relatively strong hands-on ability, to be bold and careful, at least to ensure that machine dismantling will not make mistakes .




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