10 days out of warranty my front microphone died.
The repair was relatively easy though one has to be so careful when removing the ribbon connectors. They can easily bend on removal. I disconnected the battery before removing the display cables (not shown on the guide). Reassembly is tricky. The new assembly cables need to be bent and folded back to match the original and the components have to be carefully slotted into place before holding the speaker cover in place and inserting the screws.
What caught me out is a very thin, tiny self-adhesive film over the microphone that I did not even see. After completing the repair the microphone was almost completely muffled (unusable). I eventually repeated the entire process and discovered the plastic film (now stuck to the speaker grill rather than the microphone). After peeling it off the microphone works perfectly. Success!