Subscribe Forever Tech Youtube Channel to get the latest video updates Assalam O Alaikum friends I am Nadeem Robin and you are watching your own channel Forever Tech so friends lets talk about the another PCB that has come for repairing so today we have O General Dc Inverter Ac and I am going to describe it completely that what things are installed in it and what functions are in it and how does it works but today as you can see I have the same model here for repairing this PCB is in working condition but there is some fault in it but this PCB is totally dead and in this PCB there is serial ccommunication error which means that two blinks are shown in the indoor PCB and it is not in working condition now we will turn it on and show you that it is not working at all and except this what you have to repair and how can you do it so lets give you the complete demonistration as you can see now we will give the electric supply to the PCB and then we will check what is the fault that its turning on or not but let me tell you one thing over here as you can see it is same PCB of same model but here are two reactors connected in it and the reactor in bigger size is not connected over here so that's why we will give direct electric and then check it And in our next video we will tell that how these reactors can work and why doubles reactors are installed here and now we will give the electric supply but give the electric supply properly there should be no mistake as you can see the N is for neutral and this white wire is neutral and this black wire is for line as you can see as properly is written over here and third one is for communication and except this its wiring for this we have already uploaded the video related to it if you haven't watched it yet so you must watch to get benefited from it and then you will learn that how can you do this and now we will give the electric supply then we will check it properly that it is doing switching or not now we have install the electric as you can see that there is no kind of switching over here because it switched till this time so we will plug the wire out now we will open it and check out what is the fault in it and properly check that from where to start and end as you can see we have opened the unit but first we will test it physically that is something damage or burned in it or something short circuit if we see this side I haven't cleaned it yet but here I haven't seen any problem yet but as you can see at this side some repairing has done already it means that someone has done some wor over here and if I see at this side so earlier someone has done the work as someone has done work this is the PTC sensor and some work is done on it as well and except this as you can see let me zoom in there is some problem with its fan and you can see its print has faded out so it means that someone has already done work over it but it doesn't matter let some work done by us as well and lets see what will be its results here now we have checked it physically as we have sought out a minute problem but beside this we are going to check it properly because it is completely dead for testing the dead PCB the first point we have to check is there fuses as it is very important to check the fuses we have set the meter on continuity mode and then on contunuity mode we will check its fuses as you can see contunuity mode and its absolutely working and as we have checked the sub fuse and as you can see this is main fuse Main fuse 20 amperes and 5 amperes fuse is installed here after this the PTC sensor and after this as you can see a transformer type thing is attached here and soon about this I will make a video and tell you about its functions it has a very important function because it is present in some units and in some it is not and if in some units it is present so you should know that for what reason it is installed here so lets proceed further and lets test these things now here we will rotate the PCB after rotating and if we check the position as you can see here it is written CT1 and then R1 now we will test these both as you can see we have kept meter over here so lets check it there should be some ohms given on testing and here we get some ohms as you can see 0.7 ohms are given and except this if we check its PTC sensor so we should get the values of ohms upto 43,45, 50, 60 and as you can see here we get 43.6 value of ohms which means that the PTC sensor is absolutely fine as you can change the polarity as well so the value should be same and it is showing its proper position and after testing it and after this what you have to do is to check its line reactor and reactors are attached over here as well then check these reactors and I hope you know that how to check the reactors How to test the reactors I have already upload a video related to this but here are two reactors so for this you can use the same procedure and now here after testing these things what you have to do is to check its rectification and how can you check the rectification so for this what 's the procedure so set the multi meter on the diode mode and then test it on the diode mode keep the positive side at any end and negative on other and then start to test as you can see the meter is giving some voltages for a while and then they diappeared it means that this position is absolutely correct and after this there should be no value at any point if you test it againso ther should be no value at any point as you can see and after this change its probes and after changing its probes we will check it there should be some values given by the meter as you can see the value given is 0.941 volts which means it is absolutely fine 5.20 volts and 5.0 volts and the values should be same so this rectifier is absolutely fine and there is no problem after this we will check its IGBTs so for checking IGBT test it at any point and at this place it is absolutely correct at this place the value should not be zero ,zero and if it is common so that doesn't matter and if it is not common so the value should not be zero and here at this point nothing is common and you can see we are checking it at each point as you can see and it should not show any kind of problem here as you can see it is absolutely fine and it is not showing zero value at any point as you see these are diodes and now we will test it and it is blocked from one side and on other side we get 0.375 volts value is shown and at this point it is giving the same value and if we change the probes so it should not give zero value and it should be block and it is blocked over here it is absolutely fine and its position is correct over here so lets check its IPM and how can you check the IPM so for this I have uploaded video related to this but it is a bit different to check different IPM you should know about its data sheet and except this you should know about its pin and about its position and if we see the pin so this pin is neutral and the inside one is the positive and after this these are U , V , W And like this we check it with same procedure and I hope you will watch that videos and then test them and at this side we have test its high side and except this we have check its IPM and you have to check the IPM by watching that videos and then according to that videos you can check the IPM you can check the pins through its data sheet and after this if the position is correct and the high side is absolutely fine so then you have to check its SMPS and except this these are capacitors and if these are short circuit or there is fluctuation so it can cause the same problem and here I have check it physically so there is no fault and except this we have checked it so you can test it in the same way as well and if you test it out of the system so this is more best lets proceed further and discuss what is the fault in it because high side is absolutely correct and each point seems perfect and except this when we checked its fan connector position over here so we founded some damage over here which means that there will be some problem in the fan circuit and the fan circuit is directly installed with the SMPS so its means that there would be some fault in the SMPS
