Vince pls don't lie to us, that is you and your wife in the thumbnail and you look very happy together.

No one has the right to be rude to a man of your accomplishments.

99% clean IPA is NOT conductive. The already failing 375mA rated fuse and surrounding area was hot and by putting cold IPA on it, caused a thermal shock that caused it to go open circuit.

I just have this image of Vince combing through the house praying for something interesting to break. Sometimes even contemplating giving something a cheeky nudge off the top shelf to help get the ball rolling.

the PP component is a PTC fuse, It increases resistance as the heat increases. When you inject the IPA, it also means you cool it down, so the resistance decreases, the current through it increases and overloading the fuse next to it.

Thanks for the videos. You, Joey Does Tech and Tronicsfix have inspired me to get into all my broken guitar pedals and get em sorted. Love the variety of stuff you tackle!

Well done. I believe the item marked PP is a resettable polymer PTC fuse (Bourns MF-PSML300), available from Farnell et al. Many operational explanations on Interweb. 99% IPA is typically 1% purified water, though there are some dubious suppliers. Such a high resistance has very little effect and many repairers use it as a poor-person's infrared camera.

For me, your videos are worth watching for the discovery of the issue. Yes, the fix itself was fairly straight forward but there were plenty of interesting little bits you discovered to get there. Keep up the great vids Vince. Love them :)

Hi Vince! Came across a video of yours and now I can’t stop binge watching your channel! Thanks for teaching us and helping keep devices away from landfills! Cheers from Portugal

I had an Oral B toothbrush that I replaced the battery in three times. Lasted about 14 years as a result. Still works, but it was looking a bit tatty so I got a new one.

Hi Vince. I'm a random dude from Brazil. Fortunately I do speak English so I understand everything you say. I really enjoy your accent and the way you explain everything. RESULT!! Cheers from sunny Rio de Janeiro! I'll keep watching your videos!

Another very good fix. Nice and re-gnashering.

FWIW, you can easily take off the bottom end by placing the toothbrush on the charging base, pressing down and grabbing both the base and the bottom end and tilting the brush. It's really easy. It's much harder to remove the top insulation ring.

The thumbnail was just perfect! It really put a smile on my face, so thank you Vince. Happy Easter!

Great videos as always. I need to repair one of my tooth brushes also.

As I'm walking down the street, some guy comes out of a small workshop and says to me "hey, wanna come and watch me fix a kitchen blender?" and I reply "WTF - are you mad, no of course I don't, so p1ss off!". Vince uploads a video of himself fixing a kitchen blender - me rushing to my PC to watch, grabbing some crisps on the way.

Hi Vince! When I saw this video recommended by KZfaq got a real flash back to the few years ago :) thanks for the initial recommendation of my channel and thanks one more time for mentioning it again! I must say the whole video I was thinking what I will write in the comment and the whole time I was "complaining" why did you not made your research!!! You could have saved so much hassle.. but you are right what you learn on your own mistakes stays much longer. That said I believe your toothbrush is still in danger one thing is that you put the rubber case part under the plastic ring afterwards, this compromises water tightness strongly, other thing is the hole in the bottom cover.. it is ventilation hole but with a membrane (for small amounts of water condensate to escape) now your toothbrush has a hole in it where water can easily enter.. and these brushes don't tolerate water as much as philips toothbrushes do.. motor corodes and not much can be done there.. so check eBay for some dead genius brushes just to get the bottom cap, and revive one more motherboard as this defect is really wide spread :( I started repairing Philips and oral-b toothbrushes for People locally and was overwhelmed with request for repair.. this made the tall on my KZfaq channel as last video is almost one year and have tons of material that I have filmed but can't find the time for video editing and uploading.. anyways thanks for the good memories and keep on learning!!! Cheers

Great watch as always. Think this is a common fault as my brush (same one) is just over a year old and looks to have same fault. I won't be able to fix mine as I don't have the equipment but it's ridiculous that brushes costing that much go faulty so quick with the same issue 😔

Right pain to fix these, good effort.

Hi Vince, resistances of 1M and higher are considered as complete insulators up to 1000v, you wont damage anything with 1M ohm connection let alone 5-6Mohms. It was something else that blew it. Love the video ❤

My 2010 Oral-B was awesome, that thing lasted from 2010 right up to 2022, only reason I had to replace it was because the battery was degrading, and the rubber grips had all but completely worn off. Bought my new Oral-B in 2022 (Looks identical to your wifes one but is black). My 2010 Oral-B, you could open the base very very easily, the plug had a little bumpy bit on it that was designed to fit into a hole in the base to turn it (sorta like an allen key), you kept unscrewing and eventually the bottom came off. The other nice thing about my 2010 one was that the charging base had a holder for all the toothbrush heads too. Still, I do like this new one, battery is still going decently strong in it, lasts about a week to a week and a half (Almost a fortnight, almost!).

The IPA resistance is in the Mega Ohms, it also looked a bit dirty which might affect the conductivity. Mega ohm resistance won't affect much and certainly couldn't blow anything. :)

love the vid vince happy easter george

Interesting fix. Had myself a Braun Oral-B type 4728 between 2006 - 2022, and was recycled because the battery didn't hold any charge anymore. I guess it could've been replaced, but decided to buy new battery operated toothbrush instead. Took the old one apart, saved the motor which has good metal gear in the axle, and few other parts too, recycled the rest of it, including the charger. When I took it apart, managed to destroy the charging coil, so that was the thing that doomed it. Now I wish I would've kept the pcb as well, as it was otherwise working ok, could've had some spare components there.

Happay Wife - Happy Life. Nice fix.

Love the thumbnail!!

Haven't watched the full video yet just heard you describe the issue, mine had this problem multiple times. I keep having to replace a fuse, always the same one. Leads me to think there's some issue somewhere else that makes the fuse die over time. I'm curious to see if your issue happens to be the same and if you've figured something more about it than I did.

🤩❤️ Great video, think this not the conductivity of IPA but the temperature drop make PP reset pass current into E fuse and blow then suddenly Stay mysterious why originally PP fuse might be faulty by time bc never reset for too long little bit like a switch contact melt on surface ( here microscopic size )

Glad to see Vince is starting to appreciate the hidden dangers of excessive isopropyl alcohol use, the IPAA meetings must be working...

Nice fix Vince. I am sure wifey is very happy now. Happy wife, happy life!

honest question to ask Vince. Nothing in my opinion is embarrassing to ask.

Finally a clickbaity thumbnail that celebrates its clickbaitedness. What a champ, Vince. Loved it!

22 mins in, so far, same fuse as on mine. That SMD with the PP lettering is a Bourns fuse. It is resettable.

Every time I see Vince using a toothbrush to clean something horrible, i always seem to remember him saying "just using my wife's toothbrush to clean this up". Anyone remember what video that was from?

I have used Braun Oral B for decades. I have the older style with a larger battery, which no longer holds a charge (does not have an indent on the bottom). The newer one you have has the indent on the bottom has a much smaller battery. It will be interesting to see how to replace the rechargeable battery, as I assume that's going to give up the ghost next.

When I saw the picture from the video, i thought it is not from you then when I checked who made it, I got shocked it was from you 😂

99% IPA is fine Vince. I’ve drenched boards with it in the search of shorts before. Never had an issue.

I have a 14 year old ORAL B electric toothbrush and I've used it regularly. It's a very impressive toothbrush, I haven't replaced the battery at all in it's lifespan and the battery still lasts a week before it needs a charge! This is why I like NiMH compared to lithium. Sure it has less capacity but it lasts WAY longer.

Changed about 4 batteries at our repair cafe. On toothbrushes very delicate

The motor pause at 29:59 is the toothbrushe's timer. It tells you when to move to a different quadrant of your mouth. This is a feature and not a problem.

Vince always keep your fingers off the meter probe ends as instead of a component showing open circuit it will show ‘your’ skin resistance.

Now I know about the E fuse :D

While checking resistance with your meter do you have your fingers on the metal part of the probes?

Test the IPA in a clean container. Contaminates affect the conductivity of a liquid. I would guess the PP fuse is for the motor and the E fuse is for the electronics. Also, conductivity in the several meg ohm range is just this side of nothing. You'd get a similar reading testing the skin on your hand.

Congratulations, you have just invented a variable liquid resistor :) Get it to market mate lol. Seriously though great fix nice one.

Mine went just like this. Wasnt holding charge. same model. Thought battery failed- Had recharge it daily. Turns out I was simply plugging it in on the 110v side of the bathroom socket. They need charge at 220v. 😂 Working perfectly again on 220v side of wall adapter!

The component labeled 'pp' is likely a Bourns MF-PSML300 PTC (Positive Temperature Coefficient) resettable fuse. Meaning the resistance goes up as it heats up. Additionally, the person that said IPA is conductive was either not using Pure IPA, or more likely was just being an ... Yes, even pure IPA is slightly conductive, about 20 Mega Ohms over distances less than 0.5 mm. However this does not electrically influence any household circuits because even at relatively high voltages like 400v or 600v and short distances like 0.5 mm, this will result in only 0.1 mili Amps of current flowing. This is also the reason why Mega Ohm resistors are rarely used in household electronics, aside from some exotic speciality applications fractions of a mili Amp are just not useful for most electronic applications.

What you need to replace the fuse is some of Sorins "specially calibrated wire", Electronics Repair School

That PP component is very likely a PTC Thermistor put in series with the motor made as a overload protection. it is meant to have a certain resistance and the higher load you get the hotter the thermistor gets it will raise the resistance and reduce the current through it. it is the same way a re-settable fuse works. the PTC enters a avalanche state where the thermal state heats it up enough to start increase resistance and the extra resistance increases heat which increase heat even more and you get the point. these PTC components can´t cycle endless amounts before they eventually fails

The guess is that most liquids are conductive but alcohol dries off on its own and so is better for cleaning electricals. Good work on the mend, those things are pricey. I dont know if they all do the same but my toothbrush lasts ages between charges so the battery itself should last years before its chargeable life is through.

Great choice of thumbnail 😂😂

I paused your video and did an experiment, i used 4.5 volts and an led from an old pc. I ran the led positive wire straight to the 4.5 volt power and ran a wire from ground of the led and a wire from the negative on power supply, i exposed the wire on both ground wires and filled the lid of my ipa and filled a drink bottle lid with water, when i dipped both ground wires in water the led lit up, but in ipa it didn't do anything. Hope that helps you out

We need to get my mate Vince to 1mill subs

How timely Vince. I have the same brush and it failed yesterday with exactly the same symptoms. This seems to be a frequent fault in these Brauns.

In answer to the IPA conductivity issue. I repaired a high end power supply, replaced a component in the PFC Circuit but the IPA hadn’t completely dried or evaporated. When I switched it on it took out about £100 pounds worth of components. I was not happy as the unit worked but just needed a cap changed for preventative maintenance.

Even (pure) water isn't very conductive, let alone the small quantity in IPA. Organic, non-polar solvents (IPA) do not support the flow of electrons easily so can be considered non-conductive. I suspect the PTC device was damaged (further) by absorbing some of the IPA (possibly because it had already started to delaminate). I imagine the PTC device is to cut off the power if the toothbrush is left on for too long (so it is intended to heat up over time). When the faulty PTC device was exposed to IPA and possibly absorbed some, it may have briefly gone S/C and thereby blown the 'E' fuse.

Just a thought on videos when you're measuring ohms... I noticed you touch the ends of your probes when testing which would affect the reading as its goung through your body. If you touch both leads with fingers on either hands you'll get a reading, so not sure if that plays a factor in your measurements.

Not sure if it's the camera angle. But it looks like, you do the first mistake they told as at the school not to do, when you measure something with DVOM. Keep your hands(skin) away the leads(metal parts) and or the part you measure.

Every 30secs not 15secs :) It should be 30secs per quarter of the mouth for 2mins of brushing in total, at the end of the brushing cycle it gives a couple of pulses to let you know you are finished.

Interesting to see with IPA, have you tried the conductivity of deionised water?

I think the pp is a PTC fuse and thermal shock could have been the short however that little chip could also have an oscillator running at several MHz and capacitive loading by IPA could have caused the oscillator to lockup and caused an internal switching transistor to latch on blowing the fuse. most things become conductive and capacitive at high frequencies

Hi Vince, i very like your videos keep up the good work, IPA and water (distilled water) are non conductive liquids in their pure forms,,but when you add another chemical like salt or lets say flux it becomes a different matter, that's why you should never use liquids on a live circuit, your test with the cap of a bottle doesn't prove anything other than the liquid is contaminated. hope it helps? best regards from Denmark

Nice! 🙂

Ipa and even 100% pure water are not conductive, however both are incredible solvents. Over time both will naturally gain conductivity as impurities are introduced. This is why you put the ipa in the cap and never put that ipa back into the bottle, as your brush will slowly contaminate the pure ipa.

I'm no expert, but I think the conductivity depends on how pure the IPA. Similar to how distilled water is not conductive, but tap water is. It's the minerals that make the tap water conductive, whereas distilled water has no contaminates so it is non-conductive. The IPA could have some contaminates straight from the manufacturer. Another thought is that when you floated the IPA across the components, it picked up some contaminates that were on the board.

All the smds marked pp I could find are different types of diodes from zener to TVs diodes not a fuse my guess is their using a zener as a cheap as voltage regulator

I used to clean retro computer fans by submerging them in IPA, while powering them. This not only cleans the fans, but also creates a nice table fountain. :D So unless the IPA is not contaminated it is not really conductive. Would be in the mega ohms.

nice title, had me going for a sec 😂

If it's 100% IPA it's safe as far as i know but if it's less than that the impurities will conduct current. So check your bottle label! Also if it's purely for finding out which part is faulty use a cotton bud to dab it on components in the area as this won't conduct anything if it's just a blob on the top!

My wife's toothbrush did exactly the same at the same age - hoping there's a fix!

Moved to Sonicare:) used oral-B for about 20 years and Sonicare is much better

13:10 me screaming through the screen, "LOOK IT ON THE INTERNET YOU SILLY GOOF" 😂

Vince, you must have got brownie points for fixing your wife’s electric toothbrush 🪥 though! Well worth doing and a video too! Win - Win. 😊

For an item to heat up like a fuse or resistor it needs a higher resistance, think of Ohms law, the lower the resistance the lower the heat it will dissipate as there will be a lower voltage drop across it for the given current, I x V = P so it actually works the opposite to what you would expect.

Why is there a PP fuse and an E fuse in series? Is PP realli a fuse?

SO I have the same Toothbrush it does that like stutter at around 30:00 because its counting up every 60 seconds. Normal operation Vince.

same for me last week used IPA to clean battery connectors on an apple trackpad, left it to evaporate and the unit was dead, tried again next morning, powered up again, sadly unit was still unresponsive to touch despite connecting to the puter.

Hi Vince! Long time viewer from Canada here where I've been employed as a chemist for the last 29 years. As such I can assure you that Isopropyl Alcohol is NOT conductive. IPA is an acid. And while it is true that when you dissolve an acid in water it will dissociate into ions which ARE conductive, because IPA is one of the weakest acids around it does not separate into ions when dissolved in water. It is the ions in water that makes water conductive. Since you're using 99% IPA I can assure you that you have nothing to worry about. IPA itself is NOT conductive at all. I'm not sure who this rude person was who claimed that IPA is conductive but you can take my word for it, it is not. Hope this helps. ♥

Vince do you want a Phillips Sonicare 9900 Prestige? It charges fine and the motor works. However the brush head doesn’t properly engage. I’ve been considering throwing it out. It’s yours if you want it!!

IPA can be conductive but it's minimal, however, it depends on what it interacts with, bits of solder or metal dust etc can make it conductive at that point.

Isopropyl alcohol itself is not conductive. A 99% or even 70% alcohol/water solution will only be as conductive as the water portion, inhibited somewhat by the alcohol. It is conductive enough to worry about, though, so don't run the electronics involved until they're completely dry.

According to a Google query, 100% IPA is non-conductive. But most IPA has some water in it and will cause the solution to be conductive. IMO, the reason the fuses blew was due to the motor degrading over use/time causing more of a load; so replacing with a larger fuse will compensate.

I’ve soldered the PP’s, haha. Made me laugh.

Pay attn to your multimeter! The IPA reading had the decimal point to the far left, while the water comparison was one step to the right (I didn't catch the actual ranges detected), indicating that the water's (tap? distilled? deionised?*) conductive resistance differed by at least a factor of 10 * An interesting & quick experiment to conduct: check resistance values with your local tap water compared to deionised, distilled, mineral & sparkling: you may be surprised by the results! If probe testing SMDs on your mat, be sure to clean at least that area of the mat thoroughly first to avoid debris/contaminants mucking up your readings (or use a clean sheet of paper?) To replace most 'rubber' seals easily, drop it in boiling water for a minute or 2: this'll soften it up without risking scorching from a hot air gun

Isopropyl alcohol isn’t conductive in its pure form. But it can conduct a very small amount of electricity as a 70% alcohol-water solution. Pure isopropyl alcohols have covalent bonds. Hence it can’t ionize itself to lose free electrons. So, isopropyl alcohol is electrically non-conductive. Compounds with ionic bonds tend to break into ions when dissolved or melted. But covalent compounds are deprived of this property. The absence of ions deprives the covalent compounds of carrying electricity/charge. Most alcohols have covalent bonds in their atoms.

I laughed when you said i soldered the pps 😂

Hey Vince, I'm curious...when you hit 1M subscribers, what big announcement/project are you going to take on? I mean, it's gotta be bigger than the Cheapest Rolls Royce in the UK, right? Cheers mate!

Dear Vince, why in the great mount of everest you didn't fix the other toothbrush when you knew the fault on the white one

Very common fault on the 3771. I wonder if Oral-B got a bad batch of fuses? Mine had other issues so I fixed it by buying an old but working 3771 (wrong colour) and swapping the guts over.

IPA won't conduct a huge amount of power and blow anything directly but it might conduct enough to mess with something sensitive like a mosfet gate and switch it on when it shouldn't be. The square thing next to the fuses looks like it could be a mosfet. I don't know why that would blow anything either in this case, unless it's part of a switching regulator circuit on the other side.

The small fused was blown, because you cooled the resettable fuse with IPA thereby sabotaging it and making it no longer limit the current. The protection in resettable fuses relies on them becoming and staying hot.

LOL I just fixed my sonic care 5 min ago !! :P Dead battery!! And it had a charge but really low mAh

I've never found it much of an ordeal to use a manual toothbrush! Still interesting to know more about how these things work though.

You can buy a freezer can to look for hot spots. Been using that since the 1980's

Perhaps the irregularity is due to the fact your fingers are touching your test leads. I do believe that the human body has resistance.

a PTC device is a positive temperature control device see other comments below.Even electric tooth brushes are full of tiny electronic parts well done Vince glad I dont repair any thing any more

Hi Vince … could it that as the PP fuse is self resetting that it was resetting whilst you were trying to measure it?. Also, why not get a resetting fuse so that it shouldn't need to be replaced

Isopropyl alcohol itself is not conductive. A 99% or even 70% alcohol/water solution will only be as conductive as the water portion, inhibited somewhat by the alcohol. It is conductive enough to worry about, though, so don't run the electronics involved until they're completely dry. In conclusion, isopropyl alcohol(IPA CAS67-63-0) is electrically non-conductive when pure, but can conduct a very small amount of electric current when diluted with water. A 70% isopropyl alcohol solution can be used to clean electrical components and contacts safely and effectively, as long as proper care and precautions are taken.

Place the toothbrush on the charging cradle, hold both and twist them against each other. 🙂

I don't know about IPA, but at work for a Leak detection system we were curious to see if Alcohol ( in our case + 70% rum ) was conductive, and we were able to pass a signal through a small droplet with out the wires touching each other, so while Alcohol is mostly non conductive as the internet says, you can still get electricity through it, I'm guessing it's through the other small percentage that might have small amounts of conductive minerals floating inside that the electricity jumps between. But I'm no expert either, just something i found out while doing some tests on my own.