How can I get melted chocolate out of a USB flash drive connector?

Melted chocolate got in the USB connection end of an important USB drive; it was in a pocket with a chocolate.

It’s now not detected by the computer. I’ve read about isopropyl alcohol (IPA), but would this work? Are there any other ideas?

You might be better off using naphtha, such as in charcoal lighter fluid, than alcohol, since naphtha dissolves fats (cocoa butter) much better, it does not absorb water from the air, and it is comparatively inert to most plastics and to metal.

N.B. Naphtha is very flammable! Use appropriate caution.

Immerse the USB plug in naphtha, and use a soft toothbrush to gently scrub out the plug. USB drives are physically quite tough (I've had them survive a full wash cycle when left in a pocket - after drying for a few days, it was plugged in and worked well), so likely the drive is OK if the USB plug has not broken loose from the PCB.

Of course, now you have chocolate from the drive in the USB socket of a PC (unless you were thoughtful and used a hub). That would be more difficult to clean, though not impossible. If the socket is not salvageable, use a hub on another port.

For further experimentation, it would be prudent to get a short USB extension cable or cheap hub, so you don't risk contaminating the USB ports on the computer even more.

If nothing else, it helps to retrieve the data: there is always the possibility of soldering a short section of USB cable to the contacts on the thumb drive directly. If you are not skilled with soldering, ask assistance of someone who is.

In this case, you should also sanity check the resistance between the contacts with a modern style* ohmmeter (for example, a digital multimeter. Nothing that potentially loads the circuit with tens of volts). A value of less than 10 ohms that doesn't change when you wait a couple of seconds would indicate a dead short.

This is best done after the removing the case and doing as much cleaning as possible. If the contacts are hard to access, consider sacrificing an USB extension cable as a breakout cable. If you are unable to clean the contacts thoroughly before taking multimeter probes to them, verify that they have conductivity by measuring across the same pad with both probes (should result in <1 Ohm). You might need to scrape into the pad with the probe tips slightly if they are oxidized or covered with grease residue. It might be helpful to find some discarded electronics having similar gold contacts (eg obsolete PC add-on cards or memory modules) to practice and get a feel for using multimeter probes.

*What NOT to use: Insulation/Hipot testers. Simple lightbulb continuity testers. Dubious automotive tools. 1970s bench multimeters unless the test voltage/current used for resistance measurements is known.

This uses stuff you should have at home, but I suggest getting your hands on a USB extension cable to protect the ports on your PC.

I would suggest warm cooking oil. Heat it on the stove in a heavy-based pan, then sacrifice a bit more chocolate to test that the oil quickly melts it. This shouldn't be dangerously hot; you could dip your finger in without burning yourself. After all, chocolate melts in your mouth - or pocket.

Turn the stove off. If it's not induction or gas, remove the pan from the heat or it will keep getting hotter.

Then hold the USB stick by the other end, and dip just the connector in the oil for a few seconds. This will make the chocolate melt. A toothpick, tip of a bamboo skewer, or interdental brush can be used to remove more chocolate.

When you think it's all removed, try to get a bit of paper towel in there to remove as much oil as possible, e.g. wrap it round a toothpick or knife tip. A knife tip is stiffer and less likely to break off inside, but perhaps takes a little more care do avoid damaging the contacts. Tweezers may also work if fine or flat. Or use something like a wooden coffee stirrer, whittled thinner with a craft knife. Then connect it to the extension cable and plug that into a PC. You might need to take it in and out a few times, perhaps wiping the contacts in between, but it should eventually make contact through residual oil.

Oil is preferable to hot water for two reasons:

• The fat in the chocolate will mix with the oil (adding water to melted chocolate can cause it to become more solid, not less, known as seizing)
• Oil is non-conductive so won't short out connections - if any water got inside you'd need to make sure it was thoroughly dry before plugging in.

Finally buy a new USB stick; don't trust this one again.

Some of these other answers seem a little over the top. I'm not sure why someone hasn't suggested, say, the use of small caliber firearms to shoot the chocolate off the contacts. Or, perhaps you could arrange to have the drive glued onto the outer hull of the next SpaceX rocket where the heat of reentry should effectively burn the chocolate off.

Here is a USB drive, after being inadvertently plugged into a piece of chocolate. I will admit, I did not check to see if it was recognized by the computer in this state.

Here's how you fix it.

1. Remove as much chocolate as you can by straightforward physical means, like pulling it off with your fingers, wiping it with a cloth, or popping the end in your mouth to suck the chocolate off. (Yum!) Here's what mine looked like after this physical clean. The connector is still crammed with chocolate.

   

2. Run hot water over the end of the connector, making particular use of those little square holes. The chocolate will melt and wash away, because modern chocolates do not require industrial solvents for cleaning. Seriously, I wouldn't use anything besides hot water for the first round. Mine looked like this, essentially indistinguishable from its pre-chocolate state:

   

   While I don't fully recommend it, after this step, I stuck the USB stick in my computer without even drying it except for a quick shake, just to prove a point. Obviously, it was recognized and all data was intact, because the idea that it could be otherwise is patently ridiculous.

3. Crack open the plastic case, taking care not to break the PCB or damage or bend the metal connector. With some designs, like the one I'm using to demonstrate, you may be able to get the case open without destroying it. However, don't be afraid to break the case; there should be a convenient glued seam that you can crack apart with a sharp knife or screwdriver. USB drives work fine without their plastic case, as long as the metal connector is intact. Mine looks like this after being denuded.

   

   Now, make sure the whole PCB is both chocolate and water-free. While the plastic housing is probably not technically chocolate- or water-proof, most likely it is chocolate/waterproof enough that no chocolate got inside from the initial incident and none of the water from washing the connector in step #2 will have gotten inside either (particularly if you resisted the temptation to use soap or detergent).

   However, if you somehow managed the impossible and got chocolate on the PCB board, you can safely wash it off with hot water just as you washed the connector, but in this case it will be extra important to ensure the entire board is completely dry.

4. Dry the board with paper towels and/or a clean cloth. If you're paranoid, let it dry overnight. If you're impatient, use a hair dryer.

5. Plug it in, and it should work fine:

   

A couple of observations:

• I recommend using plain hot water without detergent or soap because detergent or soap will reduce the surface tension of the water and may increase the chance that the water will leak into the case.
• For much the same reason, I recommend washing the contacts before removing the case to check for additional damage/moisture, because there's a good chance that the inside is still clean and dry. You only need to remove the case to double-check that this is true.
• If my plain-water solution doesn't work, then the odds are about 100 to 1 that the problem is more serious than chocolate, and alternative solvents or complex cleaning methods are unlikely to help. If this is the case, note the next bullet point.
• If the contents of this USB drive are so important that loss would be absolutely catastrophic, well then you shouldn't be doing it yourself based on StackExchange answers involving industrial solvents. Contact a data recovery professional.