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

Question

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?

Answer 1

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.

Answer 2

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.

Answer 3

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.

Answer 4

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.

Answer 5

Most electronics will survive being immersed in water just fine, the exceptions being components like microphones and other stuff that can trap water inside, like switches, etc. There should not be any of these on a flash drive.

However, powering a device while wet will destroy it by electrolysis dissolving the tracks on the PCB.

The problem isn't water, it's water + electricity. After soldering, in the factory, the boards are often just washed with a machine that is basically a high-tech dishwasher.

To get rid of chocolate, the simplest and safest is hot water with dish soap.

But you should definitely open the case of the flash drive so you get to the bare board, otherwise water will be trapped inside the case, it will take forever to dry, and if you plug it in before it's dry, it will die.

So, first, you can open the flash drive without damaging the board. It's usually a plastic clamshell, so it should pop open without trouble by slipping a flat screwdriver between the two halves.

Examine the board to see if chocolate got on the circuit board in addition to inside the USB connector.

Then you can clean it, the inside of the connector would best be done with a water flosser with hot water and dish soap. Wear safety glasses. If it's a USB-1 connector, you can wrap a paper towel on the end of a toothpick to reach inside. If it's a USB-C it's too tiny for that so you'll have to use a water flosser.

Then squirt some canned air to flush the soapy water out, rinse with clean water, and let air dry for a few days, or a few hours in an oven at 80°C.

If you can't open it, you can still clean it with hot soapy water and a water flosser, but you'll have to oven dry it for a much longer time to make sure there is no water left inside. Electronic components can withstand 80°C for days, in fact the standard procedure to dry them before soldering to avoid cracked packages is to bake at 80°C for a few hours. Don't go above 100°C or it could melt the plastic.

Another option is to go to a phone repair shop, and simply have them dunk the board in the ultrasonic cleaner, then if necessary, replace the USB connector.

You can also send the flash drive to this company.

Answer 6

The most important part is to disassemble the USB drive to the bare PCB. Even if you break the enclosure, the bare PCB will be perfectly usable.

You can clean it with water, ethanol, soap or mixtures thereof. A toothbrush is acceptable as an instrument, but a small paintbrush may be better. Then wait it to dry perfectly and try.

Drying is important. Ethanol is way easier to dry than water. The liquid may hide in invisible places. Air flow is more important than the temperature, so a constantly working computer fan (if available) may be the best place to leave it for few hours. Various space heating equipment (if it is winter where you are right now) can be used as long as the temperature is safe to touch.

If it still refuses to work, this is because small particles are settled in hard to reach places. Just put it in a some pocket and run it with the laundry in a washing machine. Temperatures above 60 °C are not advised.

Answer 7

I'd use a combination of non-flushable baby wipes, a solvent like isopropyl alcohol (IPA) or electrical contact cleaner, and patience.

1. Cut a strip of the wipe just narrow enough to fit in the USB slot. 10~11 mm according to the ones to hand.
2. Moisten a fresh spot on the strip with solvent (not too much)
3. Gently push the pen drive onto the computer connector and wiggle slightly.
4. Pull it off and inspect. Repeat till it looks clean.

• You might want to do the computer separate to the pen drive, so use a scrappy old USB extension cable. The downside is twice as much work.

• The computer side will have chocolate pushed into the connector. This will soften as the computer heats up, and may migrate inside the shell even if you never use that port again. Use a pin and strong light to scratch any chocolate off the pins and inside the hole. Do this while laptop is cold. Even slightly chilled may help.

• If you do read the data off this drive, never trust it again. I'd suggest replacing it with a design that has an integrated cap.

Congratulations on coming up with something I've never heard of before. I've seen a tiny flake of tin foil embedded inside the plug that caused a PC to insta-reboot when the power lines were shorted, but chocolate is a new one to me.

Answer 8

How about the use of heat alone? I'm assuming dripping the chocolate back out of it with a hair dryer should

• be pretty easy, provided one is careful not to drip the chocolate into the hair dryer, and
• get most of the chocolate out, seeing as pocket heat (and physical mashing) was sufficient to cause the problem.