Irritating Intermittent 'F2' Error on £350 DYSON FAN - Can I FIX it?

Hi V. It is used to stop something from happening at a critical moment. Temperature wanted 10 degrees, nothing will happen between the range say 7 and 14 degrees (hysteresis), thus stopping something from turning on and off continuously and maybe burning out the motor or element. The way I remember this chip, is comparing it to a bow. The difference in the amount of pull ,say temperature sensor, will not send the data,ie arrow, until your shoulder can’t go back any further. Whether you pull, halfway or say three quarters, nothing will happen in that range whilst you are aiming. Perfect for temperature sensing to send data (arrow) on to a comparator, do some calculations and then activate /deactivate a load , for example,a relay or to fault code leds. The reason why I remember it like this, is because the hysteresis graph looks like a bow, when plotting rise time versus fall time. Hope this helps.

Good Job Vince 👍From what I remember when I looked at the one I have those 74HC14's take the signals from the hall effect sensors on the motor (if you look at the two motor connectors, the smaller connector is the hall effects sensor outputs and GND , 5V). I think the chip may take an analogue output from the hall effects and shape it into a more digital signal which is then sent to the microcontroller. Well done on mentioning about the floating non isolated power 😉👍

Yet another superb fix from the fixit maestro. Great job Vince.

Great fix vince saving another item from going in the bin and helping the planet again love your videos they are always amazing to watch and the process you go through you are my favourite u tube fixer always giving such informative advice.

I think after the heating worked I'd have tried freezing the cap. And then tried tapping the cap (and other parts around it) with a plastic stick. A Schmitt trigger is a unbiquitous part, try googling it. Yours was an inverting one so if you put 0v into it, its output would be logic 1. If you then slowly raise the input voltage, at a certain point, say V1, the output will switch to logic 0. If you then slowly lower the input voltage, the output does not immediately switch back to 1. You have to lower the input to say V2 (V2 < V1) before it switches back. The difference V1-V2 is the hysteresis.

Your intro is so fantastic! Never change it. It is so you.

Good afternoon Vince, great video. So a few points, first the motor. That's obviously a brushless motor and likely has the equivalent of a stepper motor or ESC circuit on the board. Could that chip be part of it, could but without some circuit tracing we won't know. I don't think the chip is a Schmitt trigger though unless the 74 was wiped off of it somehow. The 7414 or 74HC14 (cmos version) is a very famous old chip of the TTL variety and all are known as the 74 series chips because they all start with 74. The concept of a Schmitt trigger is that it takes a ttl input 0 or 1 where the voltage may be all over the place due to noise, and it cleans it up to full TTL levels. Internally it has a crossing level usually somewhere in the middle of the voltage range. If the input is higher than that level the output is high, if below its low. So that way it creates a full on, full off output from an input that may not be quite up to specs. These are normally used where you have some sensing voltage such as a button or similar that may be noisy. They toss a capacitor across the voltage to smooth it and then add a Schmitt trigger to bring it to spec.

Cool fix dude👍. I still have my grandparents old fan from around 1950's & it still works beautifully.

Vince repairs a fan? That's so cool

always nice to meet one of your Fans :P

Great video, thank you Vince!

I reckon you found the issue with the corrosion there, nice video Vince.

Nice fix. Indeed helpful if you know what the error code means, gives some direction, like the power supply board in this case. My Philips vhs vcr has intermittently shut itself down and flashing error code "2" as well, altough not in a long time now, but haven't been able to find out what this code means. It has always started immediatly back on again and worked normally, so probably not major problem.

Remember Vince that you can cool components as well as heating them, using isopropyl alcohol evaporating, or canned air, Maplin also used to sell a canned product specifically for diagnosing and freezing chips

Can I suggest that if heat seems to alter something intermittent that you buy a can of 'freezer spray' and also chill the component to see if that makes something fail. TV repair men back in CRT days would do this all the time. Cooling then testing modern stuff is much more safe to do than heating things up and trying them as hot semiconductors and chips can end up with thermal runaway causing them to fail. Modern electronics just doesn't like to be hot, but cold is fine. One way to rule out an electrolytic capacitor with heat is put your soldering iron on the metal top - that way you only heat up that one component. Animal urine is acidic, so if any had been left it would slowly eat away at things. Ultrasonic cleaning bath is the way when something has peed on electronics! Hope some of this is of use. Great video. Intermittent faults are repair nightmares!

BIG FAN of this COoL repair series. Dyson really blows the other fan Mfgs away. Mr. Vince has such a breezy demeanor. Ii's great that Youtube can air current content so quickly. Like I said, I'm a BIG FAN

Dang Vince, that's a tough one! If anything, I would've thought that it may have had to do with the connectors on the board, as they're directly opposite the chip that you cleaned and reflowed. My thought was maybe you playing with unplugging them and testing the leads, etc., that it flexed something to the point of making better contact. But then at ~12:42 you mention that you STILL got an F2 code, right before putting the heat gun on the board. So that doesn't make sense. I don't think the heat gun would've done anything. You had it off and on for about 12 seconds, which I wouldn't think would make that much of a difference with unleaded solder. Yet after doing so, it seemed to work perfectly. But, I would've assumed, like you that it was a bad cap that was causing issues starting the fan. Ugh. Those are the worst "fixes", when you do actually fix it, but you don't know why! Either way, well done, and you saved a £350 fan!

Brilliantly done, and as Northridge Fix would say, “better than factory”

Good to mention the isolation issue - the same issue was also present when you worked on the fancy vacuum cleaner.

Dyson's new slogan should be "A solution looking for a problem" Now Mr Dyson can I have my cheque please.