Microwave oven repair. Keypad modification.

here at a Dawlance microwave oven you can see under repair. This we are going to repair and what is bad with this you will see in a moment I am going to show you I’m going to switch it on in the power, and then we’ll show you So you can see now this is [powered] up, and the display is coming, but while I’m pressing on any button it is not accepting any command you can say from the key pad. Front [panels] are from the press pad. It is not taking any command. I can give anything I mean, I’m giving anything any command, but it is not receiving any command But it is switched on as you can see so I’m going to make a repair on this one and you [will] see how to do it for this one we have to power it off from the mains and then we will attempt opening the rear top cover of the microwave oven. rare sight We have to open all screws which are securing the cover. these clips We are going to open all these screws These are four in number Something like that So I will open all these and then we’ll show you later on inside After opening all the screws we have to try it open. towards the rear side and then a little on top. by this way we can open the cover. and keep this side and then later on We are going to excess inside. The power card is coming in the way. I’m going to move it from and here What we can see here is this front panel Keyboard is located or it is not keyboard but this front power panel. This is front power panel PCb. You can see we can locate it over here and Here is one screw this one. We have to open it And after opening this screw. We can access the front power panel. I’m just going to show you how to access this. after removing this screw from so we can remove the screw and then Removing [the] screw we can bring this panel off Here up down side you can see here down side there are [two] clips. We will remove we will open those And then this will come off the door we have to open and then By this way it will come off, but first we have to remove these connections these two connections from the relay We have to remove them As you can say without you can see without them we cannot remove this board and then later on this [downside] Connector also I have to remove it from And now you can see this whole panel had been come in my hand, and what is very bad is I? Could do one thing [I] had to check over here. This is [going] [to] the keyboard and Here is the PCB the power is Distributed from here here is a [microcontroller] of course one can think that the microcontroller went bad, but this is not normally the case is normally their Keyboards are going bad so for the keyboard we have to Remove it you have to open it So we are going to open these screws. I think they are [2] or [3] [3] in my case So here once I remove the second one. I would [have] to remove And then the third one also, I heard of them. That is There in the keyboard just [I’m] going to show you this is a matrix keyboard Three four lines here and four lines here 4 x 4 16, so this is 16 Matrix Keyboard 16 lines The Arrangement I’m going to show you and from here. We can open it just Pull on this, Connector, and by this way it will come off like this this strip Then this board we have to remove it as the board is there so we remove this board and underneath we [can] see there’s this plastic piece and then this ribbon cable is going in and here is a furnace panel some people are going to this there is a glue actually attached this panel is hunted by the glue, so they are going to [mpo] temperature over here pro [deer] provide temperature or here, and then they are going [to] remove the front panel, so I’m going to Remove it without temperature T1 because this is hot [bake] so the glue is already melted so I can remove this keyboard from by this way it has been removed from you can see so what is bad this one these are normally going bad and this is the Matrix keep keep at just I am going to show you a little bit about this We can remove it by this way. This is actually That’s possible We will throw it away anyway, because we can not repair this keyboard. I mean to say this Existing one. We can not repair, but I’m going to show you the idea. How we will do it the idea is We will take the circuit this whole circuit we will write [down] on a paper and then Same way we will make a connection and put it in Just press all this keyboard on this of paper, and now I’m holding on The place where the keys are the original work so now I’m going to be using this Sharp Needle I’m going to make Marks on the [panels] something like that all [I’ve] marked up to here [file] the keys so now you can see these tiny tiny marks are there which are just giving me the direction where I will have to make holes to consider and The other side here the [holes] should be produced produced and then I will make another Piece of this piece of board you can say this is the whole board yes. I am reusing it I will make holes according to these holes where the switches will be so I will populate all the switches on and According to this circuit we sell at this circuit I will connect all the switches interconnected, and then we’ll make a strip like this, but not a script language but I will use a wearing strip like this and This one. This is also already [using] processes from some old computer and these are the wires [I] will be bringing from this and We will bring it over here, and then we’ll solder I’m going to say that [over] here, but and the way I will do it and will Solder all these connections to the existing Bigger PCB just remove this Connector, I will remove it from and then here this space I will solder and then this will go so that design will be Monitor will be modified to my own design something like that. That’s what I am doing now I’m going to make a hole in [front] of you so grabbing my soldering iron so one can do this hole by using our drill machine or even [a] soldering iron can do even So I’m going to a you that my soldering iron to do this something like this as you can see so the hole had been produced and Here also the first one I have to do so this will give me this will give me a guideline Here is what you can see just I enlarged all these holes And now in my hand this PCb is this folder PCb. I? Made holes here also three holes to fix it and then then cutting over here all [displacive] so this will be some way like this and then Of course what I will do is I will mark this position As you can see these switches will go over here this is what is The best switch a small fork length press. Which is are very common, you know They will go here Everywhere all these holes they will be fixed some way like this as I put one so This way they will go in and with a pencil. [I] will mark all these [positions] of these holes Some way like this so that I Will go to the marking [I] will do it for all I Will get marking and then? According to those marking. I will solder. I will make holes in the board some way like this here and here I will make holes with a small drill machine with a tiny PCB drill machine I will make holes in and the board in the board And then [these] switches will go in and will be inserted and then on the other side [well], they will come I will interconnect and will make the cable from I will show that to you later on I will do this for all the board We are [marking] making holes in this PCB you can see this is actually my Wall 12 volt Which is not reaching to my workbench and straight as the power is not? Present at the moment instead. [I] am using it over here so these are the Whatever, just marks. I put in so according to those marks I am going to work this paper has been took up by the trails Hopefully it will do talking it [just] show you what I did So this one is a test. We are going to put this micro switch in and let it see it’s Fixing or not. I don’t know yeah. It fixed it is fixed and From here also, we will remove this paper Because no more need of this paper after dawdling. [I] am going to put this switch as well Sorry, this is yesterday netted a little bit hot Yeah for something like this I will populate all the switches here, and then later on I will show how I’m connecting here are the switches as you can see we populated all the board and Of course the other [side] I’m going to show you this one. So here all these switches are Exposed and we can press them now as the time to translate the circuit as I believe it this all circuits These this is a keypad actually the two are can making one switch the two prints One as you can see this one and the other this one when they are on the top of each other [when] they are pressing against each other they are making a contact So two wires are coming one is of [course] here this one and the other one is from here You can see and these are eventually coming to the strip where you can see there are eight conductors [this] is the strip and these lines are connected and how they are connected. They are in Matrix. Shape. They are connected and here This diagram I just made it One two eight pins you can say you can see and then the switches are connected in between all these switches So these are switches I just show in the way as they are here on the circuit So I will interconnect these according to this and the other thing is each switch out four terminals four terminals are how and there are two switches are performed in between and Two terminals are connected together. Yes I am going through on the meter polarity and we will see this is for beginners actually the experts They know very well about these switches So these are interconnected without pressing even and here these are interconnected Without pressing and while we press on these there is a switching in between these two terminals and these two terminals When we do not press on them there will be no? Continuity in between this I am going to show you Like this there is no continuity while I am pressing on I’m pressing one, so the continuity is coming No pressing the continuity is not there pressing continuity’s there, so the long side has a continuity and the short side has no continuity So we will use a switch in Some way like this this will be some way [in] between these two are these two the switch will be So this way I am going to interconnect all this wiring and then in the end I will connect wires to this two three those wires will be connected to the main PCB I will show those details to you later on while I will be populating all the wiring were here and cable also here this all keyboard populated you can see all wiring had been done according [to] the wiring Schematic or which has just copied from the Keyboard which is here you can see and I interconnected and here is the [eight] pin header. Which I just Prepared this is a old gears. We came up from which this this explained hydra had been created And here is of course this when a pin headers, I just soldered or here you can see and This was the older which was over here, and I replaced this one with this header because this is compatible to whatever Now is the time to fix everything back the rear side is like this the front side I am going to say it is like this and now is the time to fix everything back and fire the fire [of] the [ah-1] So these three screws. I just have to put it in and very our locations [are] [perpetual] is in the way, so [means] [of] screwdriver, I have to put it in [snugs] now the third one also how to put it in Now everything is smoke. You can see now the pin header I have to connect the first eight four pins or how to connect like this the other four pins also report this header on our this connector on these pin headers So tight and snug everything like this Okay now the time to figure this thing and on Here the two connectors one is for the power and the other is for the relay on the top of relay this one will go like this Okay, so I will put this thing in in there, I Should have to release that door Like this, and then fix this thing in also like this Yeah, now is okay and one screen I have to Put it in there you can see here this way, I will put In there so that this will hold this thing [this] front in its place So now the front is snug. You can see start and now the time to Switch on this machine I’m going to switch this on The offer and of course I did not put it in I will put it on later on because this glue [I] will put on [double-sided] tape, and then we will put it on first. I help switch on just You will see how this machine is written mods. So now power [has] been restored and ever see this displays coming Now the power [has] been restored And if the display is coming you can see now I am going to switch this thing on and you will see the display also now It is switched on and [reversed] counting is there maybe the camera will pick are not? [on] our speaking you can see the reversed counting is and The set is on You can see later the lamp Here is a fence and In a little while, you will see that it will be switched off five second is there for a second? now let’s So this is and again I have to Do the command now that it’s switched on the other command switch off switched off now, or 10 Second or something like that. [I] have to clear it now at zero. You can see the other command. I’m giving this one So [ten] seconds clearing up one minute clearing it up and you can see ten minutes So all the commands now are taking that keyboard [step] response is working. We’re even like the original one So this was the repair on this particular micro Go on hope this video will work you if you are in bad situation like this that you are keyboard is bad and you [are] not going to Put the original keyboard in because our original are again going bad and when he arrived say at some month It will go bad again So this will be not a [good] choice to put the original instead making this modification [whether] it’s [or] it is very very much cheap And it is very very much durable as well as if one switch will go bad we can replace this very easily very cheaply very Low-cost also hope this video will serve you thank you for watching keep on watching stay tuned subscribe and like you

Bernard Jenkins

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