Repair: Xiaomi Redmi Note 2 Power Button

I bought my Xiaomi Redmi Note 2 back at the beginning of 2016 and it’s served as both my data-phone (browsing, data SIM) for a year and as a phone-phone (calls, SMS) for the remainder. It was good value when I purchased it, although being made with a Mediatek Helio X10 CPU, it wasn’t great on battery life despite the big battery.

With its plain appearance sporting mostly plastic, it’s held up fairly well with only a few minor stains. In the two years that I’ve owned it, the first thing to give way was the battery, which was inexpensively replaced.

The metal coating on the power button wore out, but that’s only cosmetic. The bigger issue was that the power button started to become intermittent, making sleeping and waking the device a bit of a button-pressing-tapdance.

Fixing the Power Button

In April, I had acquired a Xiaomi Mi Max which took over my data phone duties. This allowed my Redmi Note 2 to take over the phone-phone duties, formerly run by an LG G Pro Lite Dual (D686) deserved to be retired due to a lack of support (Android 4.4.2), an intermittent USB contact, a failing aftermarket battery and intermittent power button. Even though I recently also acquired a Xiaomi Redmi Note 4X (as an LTE data modem), I wasn’t ready to retire the Redmi Note 2 just yet.

I went looking for a replacement part, which was surprisingly easy to find and was posted to me for under AU$2. This small piece of flexible cable contains three buttons which form the power and volume up/down buttons on the side of the device.

To install it, we need to remove the plastic shell that covers the rear. Then, with a small jewelers philips head screwdriver, a large number of screws need to be removed to allow the black plastic frame to separate from the remainder of the phone. Watch for ones hidden under warranty labels – the shell should unclip fairly easily, do not force it.

We can see that the outer shell has a number of flexible cable based printed antennas for various services, as well as housing the speaker module, etc. These items make contact through gold-plated springs/pins on the PCB, so be careful not to damage the contacts or get them dirty, otherwise you might find new problems to deal with.

The remainder of the phone looks like this, and while it looks a bit messy, everything is nicely connectorized.

Specifically, the part we are paying attention to is on the side. With a fine set of tweezers, you can unplug the flex lead from the mainboard and peel away the whole assembly which is double-sided taped to the case.

Then you need to prepare the new unit.

Remove the double-sided adhesive tape backing and align the unit with the casing in the right orientation and tape it down. Fold the cable down in the same way as the original and plug the flex back into the connector.

Once done, it should look like this. For reference, the inside of the intermittent module looks like this:

The switches are formed by the gold PCB centre area with the X-shape and the outer ring. Adhesive tape keeps stainless steel domes above these contacts which buckle when pressure is applied to short the contacts together, forming a switch. Often intermittent operation just means that there’s some oxidation of the contacts or similar, and cleaning them could get you working again. However, as these flexes are not really designed to be serviced, and a “spare” non-original replacement part is under AU$2, I’d rather not take the hassle.

Conclusion

Making devices such that they can be relatively easily repaired through the use of screw-based construction can be quite handy when it comes to fixing minor problems. When a model is popular enough, spare parts can be easy to come by at inexpensive prices. This means that attempting a repair is economically sensible and more likely to be met with success. As a result, you can keep your devices going for a little longer.

In the case of this Redmi Note 2, the part was under AU$2, and installing it took all of about 10 minutes. It worked just perfectly afterward, with the phone still serving as my daily phone-phone for voice calls and SMS use. Something else might break, but it’s still much cheaper than having to buy a whole new phone …

Unfortunately, it seems that in the pursuit of thin-ness and light-ness, more difficult unserviceable designs are now the norm, making repairs of newer devices less likely to succeed. This may be motivated by manufacturer desires to ensure that people have an incentive to move up to a new phone promptly owing to being unable to repair their existing phone or having to spend too much to repair it.

Ultimately, I’d have to say that repair is good for the environment and good for the consumer for the most part. It allows people to continue using their (majority) working device, deferring any upgrade which may allow them to get an even better model or save some money when the time finally comes. Of course, the downside is that the older device may well be out of manufacturer support leaving the software vulnerable to (potential) attack. But it’s a risk that can be managed to some extent, especially considering that having a vulnerability does not equate to being exploited as many vulnerabilities also require “stupid actions” to be taken by the user.

About lui_gough

I'm a bit of a nut for electronics, computing, photography, radio, satellite and other technical hobbies. Click for more about me!
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One Response to Repair: Xiaomi Redmi Note 2 Power Button

  1. Kerry Lourash says:

    Ifixit is a resource for repairing small electronics:
    https://www.ifixit.com/smartphone-repairability

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