Here is some information you all may find useful if needing to replace the volume button assembly on your HTC One M8. The volume buttons flex cable is actually part of the SDcard reader assembly. So i have linked the part here for your reference: http://www.etradesupply.com/htc-one-m8-sd-card-reader-contact.html
The bad thing is the SDcard reader is only accessible by actually removing the display assembly from the mid-frame. You then will need to peel back the top right corner of the thin black foam layer to access the SDcard reader. You can then loosen all areas of the Sdcard reader/Volume assembly that are held in place with adhesive and remove the part and replace in reverse order. I was nice and took some photos of some damaged spare parts from a HTC One M8 I have, so you can get an idea of what you are up against. If you need help removing the back cover and display then head to this page for guides to assist you in that process: [[Topic:HTC One M8]]
Here are some photos that show where the SDcard is located in the mid-frame and where the flex cables run through. Hope this helps you out, and good luck.
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