I tend to be the electronics repair point man between family and friends. I can pretty easily fix most electronic items. A sort of do it all repair person. So from my years of knowledge as an Electrical Engineer, let me teach you the things to look for when repairing small appliances like this soy bean milk maker as an example.
How’s it going everybody this is pete the bush today we are in my lab and i have some broken electronics that i often get from everybody that i know this in particular is a soy milk drink thing and there’s this step up converter this thing uses 220 volts because i don’t know in asia they use higher voltage and so it requires this little box to step up the voltage
To 220 but that is not the point we want to focus today on this one because it doesn’t work my sister gave this to me and usually i get broken stuff from my family all the time and i guess my interest is to fix them i want to see if i can fix them no matter how difficult it is today i just want to run you guys through the thought process of how to troubleshoot
Something like this i don’t know if i can fix this when i go into this but what i do is i just take it apart and just kind of you know see if there’s something obvious that’s broken about it the most often things could be maybe a fuse trip if there is a permanent fuse or replaceable fuse it could mean that something is indeed wrong because if you just replace
The fuse it’s going to trip again anyway i took this guy apart already so the first thing that you do when you troubleshoot is never listen to whoever says what is wrong with it you need to try it out for yourself i’m not gonna take it apart the first thing i want to just kind of use it as a typical person you know put the water in it but i’m not gonna put like
Actual soybeans or anything and then i plug it in like so like this and then i just gotta turn this thing on right now you hear it’s screaming a little bit because there’s no water you start to learn about the entire circuitry of this thing if the lid is open it also does not turn on because at the bottom over here there’s a little switch right here see if you
Push it in it’s essentially an on off switch for this thing it’s like a safety device and on this picture thing there’s also a little nub that pushes on this button so as long as you have this pushed in it’s gonna turn on and it’s gonna complain because it’s on and there’s no water so then you figure okay let me put some water in and when i did that the motor
Actually didn’t turn so then i’m like oh okay something’s wrong with the motor maybe it’s something else it could be the circuitry that drives the motor it could be the fuse it could be a lot of things so the next thing i do is okay now that i know the motor is broken i open it up then you open it up you got to do a little bit of you know kind of research first
Before you open things up so let’s look into this thing sometimes maybe you’re like oh because you’re an electrical engineer you know how to debug stuff but all the knowledge i use here is just continuity testing where does the circuitry go the 220 volt ac goes in here this is the wire it runs to the switch this is the on off switch so as long as it’s on it’s
Going to keep on going over here here here here and it looks like this brown wire goes to the circuit board the other wire which is this blue wire goes over here this green and yellow wire is the grounding so we don’t have to care about this it just got to make sure it touches all the metal points of this thing so it’s touching the outside of this heater element
And then it goes over here and touches like the cage of this motor and it also jumps over here to go to the grounding of this circuit board now this is a 220 volt ac it goes here it touches on to the heating element but it also connects 220 uh all the way here in this red wire to the motor the motor then sneaks down here and goes to one of the commutator side
And this other wire is the thing that controls the power to all the other elements so as it comes into the circuit board then it goes okay i’m gonna feed power to the heating element i’m going to feed power to the motor i’m going to feed power to whatever right so that’s what these relays here is for i actually don’t know the ins and out of all this stuff i did
Not trace out the circuitry or anything but i kind of know what what it’s doing without looking at it too deeply so maybe i am using a little bit of my uh electrical engineering knowledge here this cable here is for the front panel there’s just two buttons over here and three led lights this is five cereal it says and then the dry and soak bean this transformer
Looks like it’s a thing that creates dc power for this circuit board the 220 volt ac goes in the circuit board and then it uses the relays to control the motor the heating element and this is probably temperature sensor there’s an overflow sensor right here i think if the water goes all the way up here it’s going to complain as well anyway i didn’t do too much
Investigation in this thing so the first thing the first thing i thought about was okay the motor is probably broken this is 220 volt directly from the ac power source and then it goes to one of the coils here and to the commutator here so then i thought hey maybe it’s the brush heads that are broken so i’m going to push in here and kind of open it up just kind
Of check it out right i actually did this but i’m doing this again to show you guys what i saw push it open see i saw that there’s a little tab so that means you should push that and not just you know kind of force it open there’s a little experience to this right and then there’s this little spring you have a really long spring because as this commutator thing
Wears out you want to push this against the commutator so this is the brush head over here i just see that okay it’s not right now i just thought maybe it’s run out so then that’s why the motor won’t work but then there’s plenty of brush uh i forget what this thing is called it’s like the the brush brush head or something so we’re just gonna put this back you’ve
Got to make sure you put it back in the right way because this is the curvature of the commutator it needs to go in that way just make sure it’s like that and then we just easily push it back put it back in like that oh wait push it back in okay and snapped in place so nothing wrong with that that’s just a little bit of research and then i see that the other
Wire going to the other side of the motor the motor is going to have two wires going into it for most motors simple motors so this one is over here and then you just kind of move the wire around and i can see that this wire is this one so it snakes in here and that is the point that this comes out of the circuit board first you want to measure the continuity
Just make sure things are connected because usually things burn out when i open it i actually smell something burning so something burnt out and i’m kind of worried maybe it’s the microchip over here if the microchip broke i would probably call this entire thing dead because it will be really hard to purchase this circuit board if it’s something simple i could
Replace it just find somewhere that’s exposed metal right here some exposed metal and we want to make sure the power is going to the motor so i’m going to beep this out when i did this initially it didn’t do this i no matter how i moved it around it wasn’t beeping so i’m like okay there’s something wrong between this point and this point and i also beeped it out
Between this point which is the circuitry control point to the motor so this is the circuitry control point and the motor commutator make sure it goes all the way to the commutator when i first measured these two points uh it wasn’t beeping very much because i think there’s like some gunk that’s on top of this so you got to make sure you push it hard into this
Little solder joint make sure it’s connected you know just kind of move it around sometimes it might make a small beep and you’re like well something is sort of connected but not really so like right now it’s doing that too yeah you want to hear a long beep like that like like that okay so we know it’s really connected now so nothing wrong with this point so i
Actually did not go into the motor uh on this side i basically went and cut the tape in here and i just opened the two joints and i just re-soldered it i didn’t even notice anything that’s actually that wrong with it it looked like it was connected but as soon as i opened it up i retested it and it was connected already so i think there’s something intermittent
About these two connection i think actually is this one in particular this wire that goes into this coil it actually goes into this coil connects to the coil and then wraps around this i don’t know 100 times and then it comes back out of this uh wire over here there was a shrink wrap around this and this magnet wire was very thin compared to this big wire so i
Just removed the shrink wrap and re-soldered it put the shrink wrap back on and you can see i have this kapton tape over here that i put back i just had to snake it underneath and wrap it around and with this i actually don’t know if i fixed it or not so when i put things back together i’m not fully putting every single screw back in so you know just in case i
Did not fix it if you try to put everything back together you might just end up taking it apart and putting it back together until you maybe you fixed it or something but that’s the idea you want to put it back together as little as possible so that you can test it out first before you do the final assembly back together and i’m gonna get some more water to show
You guys that this does kind of work so we got it all put back together i have water here to make sure it turns on we put it on this nub to make sure the thing is on i got the 220 volt normally you probably want to buy like a appliance that is correct voltage especially with this things it’s going to be high wattage so you need a giant transformer normally
People would just give up it’s like this is a 220 volt appliance boom you know throw it away but i feel really good about this because there’s not much i needed to do i just went in there did like a little repairing on the solder joint i had shrink wrap over here even the little ones i had this already so this cost me nothing to repair other than a little bit
Of time i guess well i was supposed to go around putting the zip ties back in to tie it up i removed three zip ties you need to do this and not you know worry about leaving the zip ties in because you need to take it apart to take a look at everything if you just leave them in you can’t really you know take things apart so now that it’s on i’m gonna turn it on
You heard that it was it beeped a little bit because it’s i guess it’s just starting up and now when i first turned this on like this i did not put it back completely together and it did not spin and this is not my soybean milk maker so i have no idea how it’s going to work does it spin right when you turn it on well i don’t know so what i ended up doing is i plug
It in and i waited maybe it likes to heat the water up first and then it would spin so you just gotta wait for this but now that i put it together the second time i know everything worked i put it all together even have the little blade that’s down there so now let’s just wait to see that uh it actually spins while the water is heating up i want to tell you guys
Why i like to fix these things it’s because even if the item is let’s say not given to me right after i fix this i’m just going to give it back to my sister but the mentality for me i think is after i fix it i kind of learned a little bit something about the failure modes of any new item now i realize okay well with something like this a critical point of failure
Could be between the 220 volt and the joint the joint that’s right at the transformer is kind of fragile so i don’t know maybe if i were to design it i would try to have the joint connect at a longer duration because it was wrapping another wire right so maybe you want to i don’t know connect it at multiple points connect it for longer or whatnot so that’s kind
Of what i gained from this however if i were to fix a lot of the same item it might get really boring for example i was working at a place and i had to keep on fixing fm transmitters but i guess i wasn’t fixing them so much that i was really really bored because i only needed to fix like three or four per week but after several months i kind of started realizing
What the highest failure mode is i just tallied them all up and i’m like okay the highest failure mode is because of this particular reason you know these are like the top three reasons why this thing fails and then once you know this it’s like bam bam you know once you get you the new one you’re like oh this symptom is a result of this reason and then you just go
In there and fix it really really quickly oops i forgot to uh push this button and say okay dry soak bean so now i heard a relay in there click and the water is going to heat up so let’s come back to this when it starts spinning it’s fogged up everywhere else but we can peek in through this little spout over here the blade is what you see that’s kind of silver
Down there i believe the cycle starts when the waters heat up enough it starts spinning for a little bit hopefully it’ll start spinning soon takes a little while you can see if you don’t know how this thing works you might just assume the motor doesn’t work but you just gotta wait through an entire cycle there we go oh that’s nice maybe uh there was supposed
To be a cover jeez i think i want to turn this thing off it wants a spin again i think yeah yeah don’t do it don’t ah jeez okay so it turns out you probably need to put some beans in here or also just splatter everywhere if you just have water yeah you’re gonna get this mess so i think this is gonna work so i’m going to um just return this and you know i don’t
Even have any beans with me to to make this with and test it out so this is all about running this video through the process of debugging some things especially with small appliances like these because these break all the time if i didn’t fix it this whole thing would have gone in the landfill and all because of one tiny little solder joint in the motor and and
Well now we can use it some more because if you buy this whole setup these soybean milk makers are actually really expensive like 60 to 90 dollars each because i don’t know i guess they’re important and it’s not that popular and whatnot so thanks for watching everybody you
Transcribed from video
How to Fix Small Appliances By BeatTheBush
