1# Lenovo T431s 2 3## Disassembly Instructions 4 5You must remove the following parts before flipping the mainboard 6off the main frame: 7 8 9 10* Base cover 11* Hard disk drive 12* Battery pack 13* Keyboard 14 15Its [Hardware Maintenance Manual](https://thinkpads.com/support/hmm/hmm_pdf/t431s_hmm_en_0c10894_02.pdf) could be used as a guidance of disassembly. 16 17 18 19The WSON-8 flash chip (surrounded with red circle in the photo above) 20sits on the opposite side of the mainboard, under a piece of insulating 21tape. If solders between the chip and soldering pads fortunately 22overflows beside the chip as tiny tin balls attached to soldering pads, 23it will be possible to use a pomona 5250 clip to hold the chip, with 24its metal tips just attached to tin balls, thus connecting the chip to 25the programmer. 26 27 28 29The general [flashing tutorial] has more details. 30 31Currently, detecting the model of soldered RAM at runtime and loading 32the corresponding SPD datum from CBFS is not implemented yet. You may 33have to dump the SPD data when running the vendor firmware with 34inteltool, and replace the content of the SPD hex with what is dumped. 35 36(the mechanism may be similar to that on x1_carbon_gen1 and s230u, but 37I do not know how to find gpio ports for that, and SPD data stored in 38vendor firmware.) 39 40[T420 / T520 / X220 / T420s / W520 common]: Sandy_Bridge_series.md 41
