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Fixing USB disconnect on tapping in Lenovo E420

Update: It looks like this is a manufacturing fault since the issue re-appeared after a month.

USB device connected to the right (yellow) USB port got disconnected whenever I typed something. Upon closer examination I found that a fairly light tap on the bottom right corner of the laptop would immediately disconnect and reconnect the USB device.

I decided to check what's going on there and took apart the laptop. It turns out that the Express card adapter and the USB port are on the daughterboard which is connected to the motherboard and that it is possible for it to have a less than an ideal connection. I cleaned the contacts, reassembled the laptop and it does not disconnect the USB device any more.

You have to be extremely careful when disassembling the device, I broke all three tabs that held the top cover on the right (then superglued them back).


You will want to detach the right and bottom side first, then gently disconnect the left one. The tabs on the left side hold the bottom assembly from the inside and they can be easily broken.