Eventually, the headphone jack on a Sansa c200 series breaks (near the terminal for the left audio channel). It's happened twice to me personally, so I just assume it's a common problem.
This mod replaces the jack with an inline female stereo connector. It can wiggle freely in all directions. Whether or not it looks good is besides the point of correcting a design flaw.
The approach I took should even work for other audio players or similar devices, although I could understand how the implementation may be bothersome to users: the combined length of jack and plug is as long as the c200 itself. It's still portable IMO, especially if you've put a lanyard on yours, too.
I've documented this only after having already modded 1 of 2 sansa c240s I own, so some of the critical steps may be unclear and/or difficult to reproduce, and I overall feel this method is slightly difficult to execute, given the YMMV factor; it only took me 2 years to even consider trying. At any rate, I plan to mod the second sansa later. If it turns out successful, I guess I will revise my advice to sound more optimistic.
I recommend you read the entire instructable before starting, and take a close look at the original 1280x800 images if at any point things are unclear. The precision required for this mod is beyond my preference, especially the soldering involved.
Step 1: Geekspeak You Can Skip: More Background Info and Design Thoughts
The stereo jack on the Sansa line of portable media players is custom-fabricated for compactness. As such with surface-mount (SMT) technology, my best guess to explain the problem's prevalence is that while the solder points of the jack are done okay and may remain intact, the circuit traces leading up to the terminals are too thin and therefore prone to breakage caused by inevitable stress from temperature changes and tugs/wobbles of plugged-in headphones. The trace for the left audio channel is most likely to break; the jack's entrance being flush and stable at the shell can act as a pivot for plug wobbles and so by its large radial distance from the shell, the left channel's terminal is subject to the most stress forces.
A possible ideal alternative to the jack used is one that is essentially like the neighboring, springy battery connector, which also has three terminals (which is why this solution seems obvious). The jack would snap or friction fit into the casing, and make contact with wider traces on the PCB once assembled. All stress would be taken by the shell, with springy room to buffer against the PCB. Alas, the level of precision required for this is best done by professionals, and even then the space required by this suspension system could be difficult to allot in such miniature device designs. It's actually more likely an issue of this complexity incurring more cost, but I digress.
The elegance of my mod is that the replacement jack is virtually decoupled from the PCB so it shouldn't ever fail unless the jack is ripped off, which is probably this implementation's greatest obvious weakness.
Step 2: Tools/Materials Used
• Luck (TODO: loosen this requirement later)
• Epoxy (or superglue should work, too)
• Soldering iron/flux/solder/desoldering tools
• Wire cutter/stripper (or scissors/knife)
• Inline female 1/8" (3.5mm) stereo connector (prefabricated onto a cord):
I sourced mine from an ancient RadioShack volume control adapter (male end to vol pot to female end).
You can get one from an extension cord (male end to female end) or perhaps even a converter cord. It's possible to obtain from Hong Kong for 1 USD, such as from here:
However, it's recommended that you use one which has a tapering strain relief on the female end that at some point snugly snap-fits into the 3/16" (5mm) hole for the stereo jack on the sansa c200 casing. This requirement is ridiculous to enforce but I will suggest it nevertheless, if you have ever accidentally tugged on your headphone cord.
Step 3: Disassembly
Arrive at the c200's internals laid out before you (pictured is a c240 v1).
Remove the battery cover. If you've never removed it, it's easier to use a rubberband to obtain some grip.
Slide the back cover towards the PC connection jack (right).
Remove the two screws near that end, and lift the battery out by the black tab near that end.
Pop out the outer back casing (black on mine) up and outwards towards the opposite direction (left).
Remove the last screw on the inner layer of the back casing.
Pry apart at the seam for the front end of the unit.
You may find it helpful to use your fingernail or the like to carefully push the PC connection jack outwards (toward the front/face).
Step 4: Prepare Sansa to Accept a New Jack
Remove the old stereo jack somehow, preserving electrical contact points to solder a replacement.
This is where it's unclear, as I warned earlier. Out of frustration with the broken jack two years ago, I removed mine by brute force. If I recall, what I did then was to plug in a plug and then lift the jack from the PCB. It was more of a yank than a gentle lift, however.
I'm surprised the sansa still works and that nothing else broke. The middle terminal (right audio channel) remained soldered intact, the tip's terminal (left audio channel) was already broken, and the base terminal (common/ground) tore off leaving a hair-thin copper circuit-board trace dangling in the air.
Of course, if you are sane, you could probably merely desolder the problematic jack in order to proceed, but the working room is obviously small. A big part of why it took me so long to fix this is in large part due to poor soldering skills; even though they've improved some, I'm generally hesitant especially when dealing with tiny components like here.
Anyhow, at this point all you really need to know is the locations to solder. You only need to preserve the middle terminal and base terminal, assuming it's the left channel that's kaput.
Step 5: Install New Jack
This is the difficult part assuming your Luck works here and in the previous step.
It's hard to tell what went wrong if the mod doesn't work after this step.
As you can see, the inline female connector is cut and carefully stripped just past the strain relief to expose a short length of cord. The wires should be just long enough to make it convenient to stay dissembled, as shown.
I shaved a bit off the top portion of the strain relief to make room for the PCB when reassembled. You can get an idea of how much material must be removed (2mm or so) by closing the unit and looking through the hole for the jack.
To actually solder the wires you must first burn away some of the enamel coating on them, using a lighter. Blow out the fires to control how much copper is exposed. I dip the exposed tips in liquid soldering flux and tin them first.
Depending on the outlook, you could epoxy or glue the strain relief at this point.
Step 6: Reassembly/Testing
Carefully "fold" the back half onto the front. You will want to also wipe away any dust/smudges from the LCD and inside of the front face's cover. I used rubbing alcohol on a cotton cloth.
If the case doesn't close completely, check that the wires aren't in the way of something. Do not force it to close or something may break.
Before putting any screws back on you will want to check that the mod worked by temporarily reattaching the battery and headphones and powering on your sansa.
Good Luck! If you're like me you will pray that the mod works and continues to work so you will never have to open this sansa again for servicing, since it's turned into a clamshell whose hinges are those wires with tiny solder connections.