This DYSON FAN won't stop OSCILLATING | Can I FIX It?

[@joelkist6493]

If you take a piece of tape, role it inside out, stick it to your bench. Then press your component you want to test on it... it won't wind up in the 9th dimension.😂🤣

[@charlesmott8863]

🤣

[@Entarra]

Bit of blue-tack would also work

[@marcelomendonca2095]

you've been watching too much northridge fix LOL so have I

[@Nick-qz8do]

Please don't do this. It will ruin the fun 🤣

[@livefreeprintguns]

I have many detent springs still currently floating in outer space.

[@CH11LER.]

This is one of the funniest videos you have made for a long time. I love that you have gone back to your roots of not having a clue but having a go anyway.

[@unperrier]

Well isn't that the case in every video? (not knowing anything)

[@nheather]

Possibly a decoupling capacitor. You connect these to a signal line down to ground. Capacitors have a 'resistance' that is inversely proportional to the frequency of the voltage. So to a DC voltage the capacitor looks like an infinite resistance or open circuit. But if there is any noise on the line that will have a frequency so the capacitor will look like a resistance, the higher the frequency the lower the resistance. The idea is to make the capacitor look like a zero resistance or short to ground to any interference but an open circuit to any DC component - so it removes the noise. They are often added 'just in case; and this is why circuits will work without them. In the worse case you might have a bit of noise on the signal but unlikely to cause any issues - more of a concern with audio/visual circuitry.

[@JasonWW2000]

Often referred to as a filter cap. Typically used on a dc circuit to remove any stray AC signals by shorting it to ground. 👍 I can't see the traces well enough on the video, but It's very likely.

[@del4you2]

That is not a decoupling capacitor.

[@JasonWW2000]

​@@del4you2Can you make out what it's connected to?

[@nheather]

@@del4you2 I said possibly - you keep coming up with these snappy put-downs. Why don’t you actually contribute and tell us what it is. You seem to be the sort of person I encounter a lot at work, very quick to put down other peoples work but very slow to put forward their own work.

[@Bloke-in-Stoke]

Great answer. Did anyone else hear the pops on the audio when Steve leaned into the now oscillating fan? 🤔Either I'm hearing things or I think you nailed it, cheers 🍺

[@typicalthrill]

Retaining ring pliers are what you're looking for to get that clip off and on. A very specific tool for a very specific part. Used in auto work a good bit. Love the video Dave! Great work! Steve, you did fine as well.

[@patrickphillips973]

As a tech we call them snap-ring pliers

[@M1LAD81]

I'm sure in the UK the shops call em circlip pliers. That's what I know them as.

[@FireyFlooring]

Interesting, as an engineer we call them circlip pliers 🤔

[@LindaHood-e3h]

A Giant Thank You, Thank You, Thank You! I have the Dyson DP01 and was going to toss it because of the ‘Mind of its Own’ oscillation! I thought I would try your suggestion and give it a whirl. After viewing and reviewing your video several times to make sure I was removing the correct little thingy. I put the fan back together and VOILA! It stopped oscillating! You are a Genius and your video is hullarius!

[@Herrikias]

Those capacitors spring free because they've seen Dave, and he inspired them to go out and finally live their life free of crowded circuit boards. The colony they set up in your carpet will have monuments to you for giving them a new life.

[@MyklBlue69]

😂

[@Bloke-in-Stoke]

Love it 🤣🤣🤣

[@nheather]

An opto-isolator separates two parts of a circuit with an air gap. So rather than have a wire joining the points on the circuit, one point drives an LED and the other side as a photo-diode. So you can pass a signal between the two even though there is a physical gap inside the chip - the two points are not electrically connected together. A typical use is where you want a digital connection between a part of a circuit operating at a high voltage with another part of the circuit which is running at a low voltage. So you form a digital connection across the airgap in the chip with light and there is no chance of dangerous high voltages getting across and damaging sensitive components on the other side.

[@nmb46]

What he said 👆

[@lucianofz788]

@@nmb46 google info

[@hublanderuk]

That is the fun thing with capacitance you can take the capacitor out and still have a capacitance reading. So taking it out fixed. This can happen as well. When I did my electrical courses in the 1990s if the insulation resistance less than 0.5 Mohms or 500000 Kohms then you had to fail it it could allowing electricity to flow. But then we were also putting 500Volts through the wires. So the reading he was saying seem a bit low for a capacitor since both sides of a Capacitor should not be connected at all. This is why a Capacitor symbol is 2 lines. I was told in electronics at College that if they ever discover a substance that could not conduct electricity then we would have capacitors that would never discharge.

[@stephensimmons1537]

Kinda like a relay but without the switch?

[@hublanderuk]

@@stephensimmons1537 or like a relay/ contactor without the electro magnetism. You could call it a light relay. 😂🤣

[@johnbaldwin143]

"What am I doing with my life?" Steve it is a question I have asked myself for 58 years and the only answer I can come up with is 'learning and enjoying he journey'! Love your channel!

[@Bloke-in-Stoke]

Ditto 👍

[@kevinbarker1]

“Buy it Fix it”channel had a similar issue 2 years ago and drew the circuit to explain why this happens. He had 3 different faults of which the constant oscillations was one.

[@steventouchton2508]

I am a new subscriber. I absolutely love your videos. I also watch channels like tronix fix and my mate Vince, but you have a certain style and humor that I totally vibe with. Instantly my favorite. Keep up the awesome content!!!!!! Thank you so much 🙏😎

[@JeffreyGroves]

Get some bluetack to stick the component down to your desk to help prevent it pinging away 🙂

[@deaconx55]

I haven't figured out how NOT to blow up leds with a battery. Way to go! Keep up the good work. Cheers

[@sammorningstar]

Its always amazing to me when you're able to track down the fault and make it right. Thank you for your service; I salute you, sir.

[@shanenorman7262]

Great achievement Steve. That was a difficult diagnosis. Persistence pays off. My Grandson and I have modelled our channel after your excellent approach. Alex and Poppy fix stuff.

[@nidostar2013]

Hilarious video. Thanks Steve. And I know it's outside of your control but I thought it ironic that one of the ads that popped up towards the end was for Dyson's imminent Black Friday event. Oh and what you are doing with your life is entertaining us! "Us" being 92, 110 viewers as at 15 Nov. Brilliant!

[@elf0cs]

Oh gosh! The first 10 seconds of the video I was shocked lol I've heard Steve-o speaking Spanish! And then I wondered...how does the rap sound...no way! I much rather original Steve 😇

[@rogercollins2653]

I completely appreciate where you are right now which I say is in the weeds I would take watches apart and try to figure out how to make them work do you know what I came up with I'm not good at that but you are very good at that you understand that clock works way better than what I do I also come here to check myself and see where my humility is when I watch you and your videos I understand that humbleness and patience is the only way to really fix anything thank you

[@petesapwell]

Well done Steve.

[@gaving7095]

Another excellent video Steve, you’re a genius! Love the content. That tiny ceramic oblong thingy can’t possibly have any practical use, I’m sure the fan will operate perfectly without it, forever 😅

[@dravernk1773]

Your overlayed buzzing sound actually made me jump........ I wasn't ready lol

[@wisher21uk]

Filter cap, probably causing the led not to light in the opto isolator, Great fix Steve well done, MMV has done 1 or 2 of them too 😊

[@davee1662]

Turned that one around nicely 👌

[@Ukmartian1701]

That video was cool ,I was totally blown away. unfortunately, the foreign voice-over meant I had to sync my phones audio to the TV visual, then muted the TV.

[@flixxl6797]

I was sooo confused when the Video started playing and I heared a GERMAN audio Track. First I thought someone bootlegged your Video and generated some german audio for it. Luckily I found the option to return to the original version.

[@sylvainc8146]

I have the same thing in French, the funniest part is the disassembly part with its rap-style text.

[@HometownUnicorn]

​@@sylvainc8146this is the second KZbinr this week that's done this. They don't listen when I ask. Tell them they don't think it's a problem, but watch this all the time on an Android TV

[@juliom6260]

Same here. But in portuguese 😂😂😂

[@MrJozza65]

@@sylvainc8146 It seems that "list" rhymes with "p*ssed" in German too 😀

[@nrgspike]

I'm confused that the 'original' version is "English (United States)", had no idea Steve is American, pretty confident he'd be just as surprised to find that out too.

[@MysticMagic2000]

Fun video and lots of what not to dos, but that is the charm of your Vids. Educational with excellent entertainment. Keep 'em coming Steve. Thank you

[@andrewgrant6516]

Fair play to Dyson's build quality. The remote control for my hot'n'cool went through the washing machine. I took it apart, dried each part carefully, left it a day, put it back together and... it worked!

[@tubaman66]

It amazes me that what should be a simple device requires quite so much electronics, but that's Dyson for you.

[@natsterjam]

Over engineered and waaaayyyyy over priced!!!

[@gorillazhead]

Over-engineered garbage.

[@idc2120]

Yeah the vaccums are pure garbage. Especially the cordless ones.

[@JVerschueren]

It's a matter of design philosophy for making something high end. Does one implement features with simple components, iterating and tweaking the design, taking longer to get it "just right", but keeping the naked parts cost low, or does one go the programmable logic route where the hardware is basically set in stone at the beginning and the software goes through the iterations to get it "working right". That's more expensive to produce per item, but it drastically reduces one's "time to market". Dyson chooses to have one hardware implementation and then implement its various devices in software, because recently graduated programmers are cheaper than experienced hardware engineers. It's a choice.

[@natsterjam]

@@JVerschueren Yes, BUT, it needs to be a good product, which most of them are not. "High end" shouldn't just look good, it has to be efficient and effective, just looking good, does not a high end product make. Over priced my friend, you can't convince me otherwise, having experience with several of the Dyson products. Dyson is innovative for sure, but nearly every single copy of their design, that I have used has been more effective and some are even half the price of the original Dyson product. Dyson vacuum cleaners don't suck! And that my friend is why they SUCK! 😉

[@vonderdornburg]

This was pretty funny. Love your videos! Thanks, I needed this as I am in the US.

[@Tommy-he7dx]

They are called Cir Clip Pliers, and they are a specialized tool

[@dany-ps2my]

Or snap ring pliers

[@Tommy-he7dx]

@@dany-ps2my He's UK Based, I've never heard them called Snap Rings over here, We're quite literal with the language, and they aren't a complete ring, But the more names to search under can't be a bad thing.

[@mainecoonman]

There are two types of circlip pliers. One is used to open the external 😮circlips like the one in this video and the other is for internal circlips which needs to be compressed to remove.

[@richardhemingway6084]

I got a circlip plier set from halfords. It has interchangeable tips and fulcrum point. So you can do internal and external clips.

[@johnpotter4750]

I do use them in fact I lost/misplaced one and have another. But I admit it not kept in my "small tool" box, have a bigger odd tool/device/vernier/hammer container. Surprisingly I use most a few ex-GPO contact cleaners along with a thin Halford magneto file and swear most quietly.

[@beogeek]

Steve, did you take note of my shakycam and decide to "trade mark" it lol nice video bro, stuffs getting more and more complicated to repair but low and behold you managed to sort it out. Nice work mate

[@mrkthmn]

5:10 DANG IT!! I literally jumped in my seat when you did that! Lol!

[@chanyphilly8266]

You must find some interesting bits and pieces when you hoover your workroom Steve! Lol 😂 another great fix.

[@DigitalFootprintsTheGamer]

Nice video I have been watching you for a long time and I can say I’m a big fan 😂😂😂

[@Deathswitch669]

The little bass drop while talking about the capacitor got me 😂

[@phillip.m]

I jumped

[@fraenkiboii]

Damn I missed it ... timestamp? I wanna laugh tooooo

[@ISquishWorms]

@@phillip.m I jumped too. 😁

[@philldoraine3549]

@@fraenkiboii 5:10

[@zul_fix]

Same lol

[@kennethphillips6006]

I’m a fan.

[@Bloke-in-Stoke]

I see what you did there... congrats. 🤣🤣🤣

[@BloodyIron]

love your outro songs have never once been repeated (so far as I can tell) :D

[@GadgetUK164]

Decoupling cap probably! If its turned into a resistor (as it sounds), it will be lowering the level of whatever its connected to. How that translates to the fan rotating always - no idea without looking at schematics. My guess is it somehow relates to a feed to a mosfet which powers the rotation, and maybe that mosfet was always on...

[@stevebell3070]

Brilliant as ever Steve , but could only listen to it in German Italian French or Spanish.... No option in settings to change it to English.... certainly made it interesting....

[@MIdaffy502]

Steve, I'm new to your channel, you remind me of... me. Those capacitors are supposed to do that when you interrogate them. However, did you know your Multimeter has the ability to test capacitors, all you need to do is use the what appears to be the select button in order to change mode for the setting your currently on. That CAP was likely leaking, and that type of cap is call MLCC based on the color of it. You'll find that cap next time you sweep the floor, if you remember to look for it. Too bad that type of cap never tells you what there value is... before they run away and hide. 🤣

[@sarahdaviscc]

Whenever I use my multimeter now I announce the mode with an American accent just like Stez 😂

[@SoSme]

wow i woulda never guessed it! great job mate!

[@umbrellacorp.]

The Dyson was obviously working for Skynet. That's why it wasn't listening to commands. Always make sure and take out the Skynet Capacitor Chips from your Appliances.🍟☺️👍

[@nelseify]

I think one of the things you could have done here, was inject some voltage on the low voltage side and then inspect it with an IR camera if you have one, that'll help identify any shorts or suspect components

[@truevulgarian]

I was thinking the same. Not an electronics expert by any means (pretty basic, in fact) but the circuit diagram made me think of an electrical switch. Maybe allowing the 2 pins he tested to be closed if there was an input voltage.

Best choice for the ending song!

[@chrisbloggs2787]

Nice 1 steve, yet another entertaining vidro,. All we need now is component launch cam, to go with shakey cam.. Lol

[@RobSchofield]

That was great fun! SPROING "Ohhhhhhhhhhhhhhhhhhhhhhhh..." The Despair...

[@fimbles1015]

Circlip pliers steve. Such a complicated design for such a simple object.. Madness!

[@hublanderuk]

thing is are they internal of external circlip pliers needed. I use them all the time since Circlips are used in the engineering I do.

[@scottgm321]

Watch makers use a product called Rodico. It's a blue silly putty stuff. They use it to hold the tiny gears and springs so they don't fly off. Thanks for the video. Yes they do make snap ring pliers. They have tiny pegs on the end to go in the holes of the snap rings. Unlike normal pliers and scissors, they open when you squeeze the handles and close when you open them.

[@tomlyne]

Your electrical short sound effect while you were poking at the capacitor made me jump. I need to get a life.🤣

[@stuartofblyth]

Don't feel bad. I'm the one who ducked when something came hurtling towards the camera on another vid.

[@Mrfort]

I`m sure there`s a suitable emogi for that sound effect

[@drunkresponsibly]

yup.. that scared the living daylights out of me....

[@tomosoniq]

Shat myself 😂

[@tomlyne]

@@drunkresponsibly I think it is partly knowing how that voltage feels, how it knocks you. ⚡

[@igor2011]

your BlurCAM is AWESOME!!! i wanna buy one for my family video!

[@holdmusic_]

Circlip pliers, useful addition to any toolkit

[@bLock_c1pher_Gaming]

And plot twist!. thank you man. another great vid. take care.

[@NikBoff]

Excellent video as usual, measure the capacitance of a capacitor, not resistence. the ESR of a capacitor is critical to its performance

[@supersoulswizzle]

Dang ad made me jump after you plugged in the fan to test the chip. Like how perfect of timing...

[@Tendemaz]

I love his style :D

[@danielhulan3058]

Ugh steve i love the final song in the video. Perfect for this video.

[@ValuedTeamMember]

BIG FAN? Ironically.. I'm a "Big Fan" too! What R the odds (really, I'm asking?). At first i thought this video was going to just be a lot of hot air. A "ringer". But under pressure from my other family members, I gave it a spin. I was wrong. It was refreshingly COoL. It did start to drag a bit at the 2:00 mark but I pushed through it. I generally don't like to "air" my joy this much (being from the States:) but it had to be said. You R the "Dyson™Whisperer", at least to me!

[@antinhumppaa]

Entertaining. As always. Thanks!

[@TheMatthooks]

An option isolator does what it sounds like. It electrically isolates two sides of a piece of kit. Normally separating the low voltage side from the high voltage side. It uses a light signal within the case of the OI and an LDR (Light dependent resistor) to protect delicate electronics (or fingers) from mains voltages.

[@Geek-a-Zoid]

This was a FANtastic video!

[@JimPatience]

Waited for the end credits music. Wasn't disappointed.

[@guidomersmann9744]

I waited for the capacitor to jump and it did! You never disappoint! Nice fix! Now call the police as a rogue capacitor is loose!

[@johnpotter4750]

I finally got one of those silicone repair mat, no more yogurt pots

[@akittsy]

circlip pliers Steve ,bloody hell😂

[@DonnyHooterHoot]

I cackled like an old Wizard when that cap went flying! Only because I've seen that movie myself. LOL!!

[@asdfasdfasdfasdeff]

bro the feels when that SMD cap went flying into another dimension. but yeah, you got lucky. replacing the cap would be a good idea but seems it may work w/out it. could have been a UL requirement.

[@idm8885]

Uncle Steve you spin me round round - like a record round round

[@OVERKILL_PINBALL]

Well done sir!

[@Saintdave71]

I cannot watch this video without the audio track cycling through Spanish, Portuguese, Indonesian, French, German and Italian. Only your video is doing this. HELP!!!

[@Fingerprintguy]

My phone plays fine, my Google TV Streamer has the same odd language issues !

[@briangereau788]

​@@FingerprintguySame for me. I've had it happen with other channels randomly as well.

[@Thug2GSXR]

Please Steve deactivate this ai translation sh**

[@johnpotter4750]

English english, rather that American english my guess ? Try Aluminium ! or Rhubarb !

[@jeffm5056]

Im your #1 fan.

[@ssdelko]

Thumbnail looks like the romper room magic mirror. US children’s show back in the ‘60’s. She would look through it and wish happy birthday to some lucky viewer!

[@thephrase22]

You’re a magician!

[@regmigrant]

general rule: capacitors never pass DC voltage unless they are breaking down so dmm in Ohms should always show mega or OL. you could also switch you multimetr to capacitance test mode - and look up how to interpet the result. hilarious response to launching it tho thanks for what you do.

[@bagofmanytricks]

Put at least the same size cap in its place, it's there to avoid sudden drops in voltage. It not being there can cause intermittent annoyances that are really hard to debug.

[@simondonald8021]

My Dyson tower fan does the exact same thing. I disconnected the linkage about 7 years ago and left it that way

[@MurrayMints]

Nice video... I see what you did with the outro music 😂

[@ShadowcasterZero]

@19:33 found your missing capacitor. It's next to your UV light

[@edwardekiert4790]

As someone already mentioned, if something turns on when it shouldn't, it's often a shorted MOSFET. When they die, they permanently turn on. Optocouplers are usually used to pass information back to high-voltage side and it's unlikely that's the culprit here. That capacitor might have been leaking a bit of current, MOSFETs don't need much to turn on, they just need to "see" voltage. That's the only explanation I can think of.

[@JyrAnt01]

16:38 Just a tip. Push the component to a piece of bluetack to prevent it to jumping in to another dimension.

[@t0nito]

The capacitor is probably leaking current, not a full short but enough to pass enough current through to trigger the circuit

[@TylerDurden-pk5km]

You can also have capacitors that fully short - but only when reaching a certain voltage.

[@JeffreyGroves]

Apparently that capacitor was starting to act like a resistor instead of a capacitor and was letting enough voltage through to trigger the IC oscillating feature. You could probably throw a new 10uF cap back on there to make the oscilliation feature less likely to trigger incorrectly when switched on or off, but that's just a quality of life thing I would guess.

[@StezStixFix]

Thanks Jeffrey! All still working well, but I'll definitely whack a 10uF in there if it shows any signs of failing! 👍

[@Swumhole]

More to the point how did you comment on this video 3 days ago when it was only posted on youtube 6 hours ago?

[@sdjmchattie]

@@SwumholePatreon supporter with early access to the videos? 6 hours ago for you and me, but that timing is when the video went public.

[@Swumhole]

@@sdjmchattie Ahh, OK, thanks for the explanation. If I wasn't such a cheapskate I'd have known that!

[@BIG_P80]

@@StezStixFix you might want to get the capacitor in there sooner rather than later as you might get a feedback frequency when you switch the fan on and off and it will blow the opto isolator

[@BlackcountryhistoryhunterBCHH]

your not an idiot you a eternal optimist

[@ralphj4012]

Well done. Would depend on where the capacitor was connected, if on the input (diode) side then basic switching protection for the micro, if on the output side then part of a snubber (protect the motor and internal triac from spikes) which usually has a resistor in series. Slightly odd use of the MC3083 if it is controlling the motor directly, there is usually an external triac or SCR. Either way (as others suggest) refit a capacitor.

[@RFWPHX]

Blur Cam. This may have been suggested before. Looks like a Sony camera in the Blur Cam position. It is probably running in multi point focus mode. You could go to the camera menu and use manual focus setting. I don''t know if your camera has a spot focus or center weighted focus mode. Those modes might work better for your set up and still retain auto focus.. I enjoy your channel. The electronic content and the music is entertaining.

[@mikireqmetal4757]

Ahora doblado al español! Genial!!!! Gracias!!!

[@BelovedPotatoRepairs]

Bye bye Mr Capacitor, thank you for your service, you flew well 😂

[@cristianmanole6812]

Sei una persona molto paziente e divertente

[@richardhemingway6084]

Result! It works with one less part. That capacitor should show as an open circuit on a 'Multimmiter'. Opto isolators are used in a feedback loop, for control of a mains power supply. Those caps are famous for going leaky, or short completely. The oscillator motor looks like it had three wires, so possibly three phase AC. That leaky cap possibly fired up the power supply, when it shouldn't have.

[@jed2055]

You need to read all the comments, not just down to the first bloke with the answer. I also learn from the people who post sulutions.

[@danw3735]

Well done knackers

[@PeterPetterssonFrisk]

Good job

[@mikehibbett3301]

You would be surprised by how many components, especially decoupling capacitors, we designers put on PCBs "just because".

[@jenshildenbeutel808]

Steve, please do not auto-translate your titles and videos. In my localized version (german) all the sarcastic, extra dry comments are lost. I am not sure if you will gain new or satisfy existing viewers that way. I'll stick to the real Steve!

[@patboy3000]

Jup, it's very bad that ai voice.

[@michaela831]

+1 for visibility 👍🏻 Why does KZbin constantly add unwanted features 😕

[@rafaelgsbr]

Yes! And for whatever reason, the option to switch the audio language is gone from my app. I had to watch this using Chrome.

[@Loki-]

Ich verstehe nicht. Does he have to turn the setting on? I think it's a great feature for general purpose use, but if you want proper content in that language, then just go go those creators. Because Steve and others in similar positions cannot afford real translators.

[@michaela831]

@ I can also answer this as I am from Germany too. Pain is that this was on by default. I would only call it’s a great feature if you really really really need to translate the video But the shitty AI voice talks with such a monotone voice that it is really hard to listen to it

[@proaudiorestore8926]

2 things, 1.) you need circlip pliers to remove circlips. No point in trying anything else. It MAY work but haphazardly. 2.) Dyson make their stuff as sturdy AF 😂 I service our vacuum every now and then. It takes me a good few hours and everytime I have to watch a disassembly video. EVERY.TIME.

[@truhse6054]

KI synchronised? I'd like to get Steve back! Und ich bin Deutscher... Aber ja, it's fu***ng funny 😅 Made my day.... Anyone seen those northwestrepair parody northridgefix related? the longer I watch the funnier it gets. Sry for grammar...

[@Lazyman1975]

Just got a tip for you when you're testing tiny parts on the bench. Lay down a piece of that foam double stick tape and lay your part on it. No more ninth dimension....

[@claytoncavalcante9130]

You can use double-sided tape to hold the SMD components before measuring...

[@FiveStringCommando]

4:08 Snap-ring pliers. At least that’s what we call ‘em across the pond.

[@jasonpatterson8091]

I kind of want to see you go nuts on this thing, like the printer in Office Space.

[@Wanton110]

There is probably a circuit for you to turn the oscillation on manually by the on/off button, and that cap was probably used to sense it and causing the problem, so by removing it, it cut that circuit so it can only be told to oscillate by the remote

[@teeslunk]

Hi 👋 Steve. Been watching your videos for a while now. And I’m thinking 🤔 of doing it myself. How best do I get into it please?? 🤙🤟✌️👋👌🤟👍🏴󠁧󠁢󠁥󠁮󠁧󠁿🇬🇧

[@chillzwinter]

The capacitor is just filtering any noise off so the LED in the opto-coupler I.C. won't accidentally turn on. Try radiating some RF noise close to the device, like a mobile phone or microwave oven, and you might see the device jitter and make a ghostly move as the noise introduces enough DC voltage to light up the internal LED. The opto couple is typically used to isolate the 240 volt side from the low voltage (e.g. 12 volt) side. When the LED is lit up (inside the opto coupler) an opto receiver on the opposite side of the opto coupler chip sees the light and switches on a transistor type component to conduct the 12 volts to the motor. This mitigates the risk of any high voltage shorts producing 240 volt on the 12 volt side and potentially killing someone or causing a fire. Not having the capacitor is not likely to cause any noticeable effect in a low RF noise environment. Personally I would have just disconnected the oscillator motor and told the customer it's buggered, but you can still use it to blow straight - but I'm lazy.