I had this problem with 2 of my HBS 700s. The speaker in the earbud goes bad and needs to be replaced. If it is still under waranty you can send it in to be replaced (trying a home repair will probably void your waranty so try this at your own risk). If it is out of waranty and you have experience with a soldering iron, the earbuds can be replaced with a plain set that look similar to the originals from your local store (Wallgreens has a good selection for like $10). I am a novice at these things but the solution was pretty easy and has worked for both of my earbuds. I actually improved the quality of sound by installing better earbuds.
You will need: - 1 small soldering iron- one set of new wired earbuds (no volume control or mic... just plain earbuds)- jewlers phillips head screwdriver- one small flat screwdriver or thin flat edge to pry the cover off.- one needle or thumbtackDirections are the same for both sides. I suggest doing one side at a time and repeating the steps for the other side.Directions: - TURN OFF HBS 700- locate the rubber plug on the bottom of the case (one on each side above the L and R symbols) and remove the plug with a needle.- remove the screw located under the plug
- use a jewelers flathead screwdriver or thin flat edge to pry the case appart. The best method is to gently pry the bottom of the case outward then push in and up on the top part of the case starting at the back of the plastic case (where the earbud wire comes out) and working your way forward.
- remove the earbud cup and set aside. (if working on left side, also remove the charger door.) - the circut board is held in place by plastic arms on the sides. Gently pry the circut board away from the case and lift up where the arms are holding it in place.
- once case is removed from circut board, you will see where the earbud soldered to the board.NOW FOR THE FUN STUFF...-cut your replacement earbuds to length and expose about 1/4" of the two wires inside (usually one gold and one colored or one solid color and one multi colored).-The two wires are coated to prevent them from shorting out while touching. Add solder to your soldering iron so there is a good drop hanging from the tip. Insert one wire at a time into the drop of solder (about 1/32" will do) and hold it there for a few seconds. This will melt the coating and allow the solder to stick to the wire.
BE CAREFUL NOT TO SOLDER TOO MUCH OF THE WIRE OR IT WILL TOUCH THE OTHER AND SHORT OUT! ONLY A LITTLE ON THE TIP OF THE WIRE WILL DO.-carefully use the soldering iron to remove the old earbuds from the circut board. A small soldering iron with a sharp tip works much better than the standard size at this. The soldering points for +/- are VERY close together so becareful not to melt them together.-solder the new earbuds in place of the old ones. + to + and - to -.-tie a knot in the earbud wire close to the circut board so it does not pull free from the case when closed.-at this point in my repair, I turned the HBS 700 on to listen for the startup tone to make sure the earbud was connected properly. I DO NOT RECOMMEND TURNING IT ON OR TOUCHING COMPONENTS WHILE IT IS ON. IF YOU WISH TO CHECK IT AT THIS POINT LIKE I DID, DO SO AT YOUR OWN RISK. ALSO, MAKE SURE NOT TO HOLD THE CIRCUT BOARD OR TOUCH IT WHILE IT IS ON AND TURN IT OFF BEFORE CONTINUING.NOW IT'S TIME TO PUT IT ALL BACK TOGETHER.-reinsert the circut board to the top cover in reverse of how you took it out. Do not force it and make sure all the plastic arms clip over the circut board securely. Make sure to press the buttons to see if the are seated right.-replace the earbud cup, battery door and power switch if it fell off.-attach the bottom cover making sure to leave the knot on the inside of the cover. The cover should snap on easily.-Re-insert the screw and plug.DONE!If you wish your new earbuds to attach magnettically to the cup, you will need to break open the old earbuds and remove the magnets from inside. Then glue them to the outside of the new earbuds or drill a hole for them to sit in and glue them in. Be careful tho because drilling holes too deep in the new earbuds could damage the wires inside (I found that out the hard way)
I hope this solution was helpful