SMPS Switching switch Mode Power Supply repair Basics & Troubleshooting Haseeb Electronics

this far satellite receiver but recharge the satellite receiver satellite receiver LED TV a TV circuits all of them have same our price same phenomena same procedure there is nothing at all different in any power supply just the design the shape may be different but the procedure is the same I will go step by step every power supply here we give 220 volt in switching modes we can give 80 volt to 240 volts protection filter circuit then any power supply they said LC filter circuit then any power supply we will compare our power supplies with this and we will make troubleshooting every power supply it has rectifier circuit here I applied a see here AC here AC here DC I have a chopper circuit what is chopper circuit it is voltage controlled oscillator our pulse width modulator we can say any component are used in this stage they are either VCO and pulse width modulator here is isolation transformer this circuit input circuit here we will discuss output circuit check one supply to supplies three supplies many how much supplies it need it's a pop - requirement of the circuit but the basic principle is here okay here I will follow through on stage here it is rectifier the next sometime it is regulator and the from this or this sometime he will take output from here sometimes from here from here or here here is feedback circuit circuit gives feedback to this circuit that there is nothing wrong with this circuit if this circuit is working properly this circuit will work properly if here any problem this will give a signal to chopper circuit if here is any problem it will stop this circuit what is here here is optocoupler from regulator we take output 220 volt input 8080 world of 240 volt perfection circuit what is perfection circuit we will see here I will start from this circuit if I come to this socket I have two bins okay if I see here one line it is coming directly to this pin what is here if I see here is fuse after fuse if we see opposite side here is fuse from here to here fuse it is written have fun it 100 now current will pass from here to here here I make input choose output the second line the second line coming here yes at the same point if we see it is coming to this it is return V a 1 0 1 voltage arrestor voltage arrestor what will happen here I applied 220 volt if there is more voltage than 240 suppose we can say 400 volt instead of 220 400 volt this will make short circuits this will burn out it will make short circuit when it is short circuit our current flow from this path when this path the fuse will burn out immediately so the next circuit will be protected so if we have Lightning arrestor it is also for over-voltage I'd like to register now from the fuse if we say from here fuse from the fuse there is another component it will sense the over current if there is any short-circuit in the circuit okay it is also safety if the circuit will draw over current same line it is also working from here it is far over current this fuse over current the same line over current this far over voltage safety here if we say here is a capacitor this is filter capacitor if then we come to this point after that current passing from here it is stopped here from this it is stopped here we will see what is this component it is an inductor our circuit stops here then current you have to pass through the inductor current will pass from this inductor where is this inductor we can see from here and within term and it will pass through through the other end it will pass to the other end there is another filter so come to the block diagram for actual circuit what we found here we fuse Tiger stuff we find three item here we finished from here in this bounced light if I come to other power supply and we will take any one for supply if I come to this power supply I have two input terminals this here fuse from fuse when this current will pass to this terminal from this terminal here it will start here this line will come to here capacitor it is for filtration and the both lines it removes the harmonics for ready frequency here I have a same inductor two lines electro inductor installed in two lines this protects for surge current okay from here this line comes here here and this line from here passing from the inductor to other side we will come here what is here here is a bridge circuit here the same we discussed LC filter that was simple supplies power supply this power supply is best it have more safeties passing through this there is capacitor there is another filter from here it currently it has isolation here we can see here from here to here this is filter from here to here this is filter when it will pass through filter LC filter and see L see L see the inductor capacitor inductor capacitor two stage filter one filter to filter some power supplies like a cheaper satellite receivers they have just one stage the best power supplies for LED for the TVs they have dual filter like this what I am showing if we see this power supply this line is coming here this line coming here okay when we come here there is a capacitor harmonics from here this line here it is a fuse from fuse this is coming to same lines parallel lines we see here is a circuit disconnected okay here if we see two line filter this one line this second line it have four terminals 1 2 3 4 I must set it to continuity here I will apply a 1 line this line is shorted here shorted if we see here is a break but it is reading this inductor so if the fuse is good I have a this circuit is working it should be open it should be open if it is short circuit that means we have heavy voltage strike on the board the same time if I will go to this circuit here I have input terminal from input terminal I have to go through the fuse this is fuse so I will pick another power supply here it is input terminal it has th 0 1 we can see we have this line here okay here is voltage arrestor by s v1 if we have here is voltage arrastre removed from this power supply voltage arrestor has been removed okay we will come to this power supply this line is line it is going to fuse Oh another example this is a sister fuse with stop here is the pastor here is the master here is the inductor okay then it will go to a bridge yes see AC this will give us DC DC will go to a capacitor positive negative we will complete our subject here very careful that is live circuit it have 220 volts ac but the most dangerous that is this evolved we set it to AC okay line common volt and common so here I will check to show you a circuit here I have 220 volt AC 230 volt AC these two point here I have 230 volt now from passing through fuse if you this damage I cannot find this voltage at this point now everything is working so 230 volt available this line fuse after fuse capacitor I will check this cable this voltage at the both side of inductor 230 volt after they are the same line I will check the output of inductor it is okay now I will come to the second inductor second coil because this phase are neutral here it is AC here I have AC now there is a bridge circuit every bridge circuit it have four terminal here this cut it have positive output terminal here and it will be connected to the capacitor positive terminal capacitor have negative and positive terminals the cut side if we will put this number in front of side and the cut is at left side so this first terminal it is positive output terminal positive positive terminal ground sorry positive terminal AC AC and this negative terminal so this negative terminal should be connected to the capacitor negative terminal see this this negative terminal so I can check voltage DC voltage either and the output terminal of the of the bridge I can check on the catastrophic so in this circuit I have two capacitors it have 350 volt plus DC voltage here I have AC until now I have at this point I have AC 230 volt but now I have from this stage I started DC so I have to select DC because here is 4 terminals for bridge circuit 1 2 3 4 ok 1 1 2 3 4 so if we see this terminal this terminal is connected to here this point and this terminal it is connected to here if we see this terminal this point is at the same terminal and from here I have one line that is written here positive plus sign if this is plus sign so this is negative sign this line it is connected to this thermistor and this de Mestral this line capacitor connected to this capacitor and this commencer so I will check for H I select a multimeter at DC amazing it is 331 volt because it have a very good filter so it is 330 world sometime this world this won't go to up to 360 or 380 volt DC okay from DC this world we will go forward okay this this okay this line now we have a chopper circuit we have a chopper circuit we will discuss in this session first I have to disconnect power another safety I have removed the plug but the capacitors are holding charge never touch this capacitor maybe if there is a fault it is now it is going down maybe if it have open circuit this capacitor will hold charge and it can give a very bad shock it can give a very bad very bad shock because it is retaining charge it is holding charge it is charged until you have to discharge it by you can use any part any metallic part and you can make short circuit with these two pins and you have before touching this we have to verify the voltage oh it is now still 150 volts it is decreasing so let's so when you are working with this never touch to this area and there is a no third one this one okay friends trust bridge circuit this bridge rectifier okay from the bridge rectifier I have to Craster's I have voltage here okay now what what is there as I discussed I have a voltage rectifier circuit until this rechecked error DC 330 volt DC here was 230 volt AC here as you see here is 230 AC when we pass through a rectifier it will give 330 volt DC now we will see the chopper chopper first it makes regulation what is the function any chopper it will sense the voltage at the output terminal it will sense the current at the output terminal and it will make pulse width modulated so it will compensate our load effect loading effect until a certain limits it will make a good regulation by increasing increasing or decreasing its pulse widths at the after bridge I have 330 volt DC the same circuit is here here I have one capacitor because this circuit is small I have one capacitor 450 volts it will give about 350 one 331 DC if I see this capacitor this circuit it have the same input terminal inductor fuse it have the same capacitor but is tiny small size it was 400 volt it will give about 330 volts at the same point after that we are going to discuss chopper circuit if I come to here here is also bridge circuit bridge rectifier which I will be discussed here he make bread from these diodes if we don't find voltage here at this capacitor at this capacitor that this cluster that these capacitors this capacitor so we have problem behind we have problem where in this area filter circuit and bridge circuit this is filter circuit bridge circuit if I do not find voltage here if I don't find a voltage here at this point this 330 will not available problem is in this area we can check fuse we can check thyristor we can check protection circuit we can check if any line open if we discuss the circuit if this semester register is okay then voltage will pass from this if it is broken from inside it will cut this path because no current will flow from this circuit so we cannot find voltage here so if we know for if we have no voltage here the problem is in this area the problem is in this area so we have to troubleshoot this area any component here may be one line from this inductor is damaged one line from this inductor is damage may be fuse methyl ester so some components it is a good idea if I don't have voltage here if I don't have voltage here I have to go in this area okay if I don't voltage here problem in this area any mobile charger any energy saver circuit any computer power supply and you television power supply TV circuits I have removed pastor from here if I don't find voltage here at this capacitor the problem in this area the problem in this area here I have a bridge circuit diodes I will discuss some discussing about chopper circuit chopper circuits as I told it will sense output voltage output current temperature based on these items and input voltage input voltage it will check output voltage input voltage output current temperature of the circuit based on these items it will change the output and if there is short circuit the feedback circuit will turn off are set to off condition to the chopper what is chopper chopper is IC chopper is IC pulse width modulator are we co voltage controlled oscillator it is voltage controlled oscillator it will give a reference we will give a reference voltage and based on this reference voltage it will change the output the circuit will make sense from the board and it will give a feedback okay we will check feedback here it is an opto coupler this one every switching power supply it have this coupler we see this circuit is separate this circuit is separate there is no connection between these tools two circuits just only our feedback circuit and this transformer this transformer we will see all the all circuits if I see this here is a line it means this circuit is separate okay this first cosplay the second power spray if I come here we can see a big cut just only this primary side of the transformer this is called chopper transformer and this is output terminal output side of me or sorry I'm going I am wrong this yes this I see this I see chopper I see it it will chop DC voltage into it will make a pulsating DC repulse for this transformer and this strongly ripples will induct to the other side okay this supply it has cut here this cut here okay if we come here here I have a description so this disconnected respected just only this I see this I see feedback I see if I come here here is a feedback feedback I see if I come to this circuit here is feedback I see here if we see there is a big transformer and one pin to pin 3 & 4 pins this if we see there is a dotted line we differentiate that this area it's separate this area is separate very nice let's explain what is chopper I take DC voltage from here this negative line okay this positive line if I connect this line to this line suppose it is an example I have if I have transistor BJT ujt FC T some time and channel and channel MOSFET some time and channel enhancement mod alpha t anything just he have to make here I have DC it have to make ripples because from transformer DC cannot pass to the other side so I have here some source driving and it is called pulse width modulated circuit let me show you if I will come to this we I will upload a separate video for participants with modulator circuit so let me explain this I see this will control the switching we say switching mode power supply so here is switching function it makes switching close on a on of on of on of of like this this circuit this IC and these components these are responsible for switching if there is any any component short in this area any component short in this area this will inhibit the circuit this will disable the circuit this is feedback circuit here is a transistor which is bei biased at a specific value and it will sense one line one output of the circuit if that output is available and it have no node so it to this optocoupler will give ok signal that means if we see if we see this line it is connected to ground there is this is ground from the capacitor dispositive line this ground if we see this line is connected to optocoupler but this line it is connected directly to the IC pin number three yeah so if there is short circuit in this area either this one is bad either optocoupler is bad up talk about never fail this never fails the problem we have here if we problem here we have here this area it will give a fail okay I will come here in this circuit here I have a chopper from chopper and if I see there is nothing connecting just only this so if we see this component it is I see - if they say I will discuss I will describe before how it is functioning if we see it have inside our here is diagram of the circuit it have led inside and our photo transistor inside this circuit is connected connected by the light when there is voltage available in this area here if we see this transistor in the other there was another transistor but here it is SMD transistor if this transistor is bad this optocouplers no gave light to this Junction and it will not work and it will cut off the circuit okay I told you the principle is same in MZ all circuits the principal will same maybe some components will different here I have this I see I have this I see if I go to this circuit I have this IC o---- this IC but here I have different type if I come to this circuit I have this icing okay if I come to this circuit it help this I see if I come to this circuit there is no I see so nice here is no I see here is only this MOSFET and it is taking direct feedback from the transformer output oh nice yes it is checking output from the same circuit it is taking the back oscillation from this circuit if there is any short circuit and it will draw more current it will cut the output of the FE T so I told you the function is same maybe some component will different so here he is using just only a city or this circuit this is VCO circuit voltage controlled oscillator circuit okay we will see here what is here here is the same technology and if we see this this this so now come to the point here he is using this component this compared this component and Athabasca here he is using this component this component this component of the capacitor but there is no I see if we see this circuit he is using I see in this circuit he is using I see in this circuit it is using I see in this circuit there is I see if I come this side there is no I see just the small IC is driving the Fe T this Fe and it will connect it to the cross harbor like here so our subject is here I give you examples many examples how there is a changes in the circuit but the basic function Amon ah is the same number one mobile charge of battery chargers any type of battery charge of computer power supply television power supply LED TV power supply LCD TV power supply this LED TV circuit TV power supply circuit if we don't have power supply so that means the problem in this area so now I will check the output voltage of the circuit and I will show you how they are working I have to complete this function here may be one line to line it depends upon any circuit how many outputs it need ok I will just take one circuit here he will use one diode he will take this positive negative here he will use one diode negative positive every circuit sorry to pester one diode every circuit it isn't the same but from here it will take the baby he will install some regulator if ice come here to this diagram after transformer he is taking active I read feedback the same here ok now I have applied power to this circuit I will give a close view to the circuit and we will see yes and I discussed we will check voltage here here I have 331 destructive permanent this negative terminal which is coming here at this stage okay now it is switching at high frequency it switches at very high frequency we can go to data sheet I will discuss about data sheet I hope so so after that it is taking this line we see 1 2 3 these 3 outputs are collected together 3 lines and we have one line here it have jumper jumper is connected to this line okay I have one line here and it has going to get to this diode yes here is a diode okay we can check this line in this power supply I have worked it from here this line and it is taking from output this line to this area and here is a capacitor one and two capacitors I can check voltage when the capacitors I have two capacitors here this is giving me 78 world oh that's nice it's working I have if I don't have voltage here maybe I have problem in this area any component bad here in this area this up the coupler optocoupler will cut the drive up to poplar will top for the drive of this I see this optocoupler will cut the drive of this circuit so if I will try to rotate because it is very dangerous while making video we can see it here are 2 capacitors 1 and 2 and this is diode this one is diode it's back-to-back two-out double diode this station diode it makes high voltage rectifier rectifications so on these 2 capacitors these are two parallel 78 volt okay so this power supply I will check the output the raf diode one diode two diodes and this capacitor I will check output at this capacitor here I have to check the output it is giving me 3 point 5 volt 3 port forward this processor voltage okay okay if this voltage are missing because up to coupler is collected in this area if this 3.7 volts are not available this will make off so this voltage are available so other power supplies it will not care it will monitor just only the processor voltage this is because process and voltage are very important in any circuit so I will check another voltage on this capacitor are you will check now radius close you so here I don't have output I have output here and this capacitor I have I have one power supply available the other power supply I don't have so the problem in this area specific area so maybe this diode may be anything in this area we can find a fault so friends if this video satisfies you and it gives a good information for you don't hesitate to subscribe my channel and you can share this video and if you have any question any question feel free to ask me in YouTube comments comments so you can follow me at se ballot Hasib elect on facebook you can follow my page and i 0 for ta facebook and in youtube this address youtube facebook has developed and you can also find my videos at you can find my videos at YouTube Seba left it is for Hasib electronics and you can search choke Azam for sure for ta one of Te faster 40 you so thanks for watching video

Channel: Haseeb Electronics

Views: 105,803

Keywords: switching mode power supply, smps, switching mode regulator, circuit diagram, switching mode power supply tutorial, basics of switching mode power supply, smps tutorial, how to repair switching mode power supply, basic working of switching mode power supply, smps basics, how to repair smps, how to repair switch mode power suppies, how smps work, how switching mode power supply works, haseeb electronics, chowk azam, electrical engineering, electronics engineering, physics, repair

Id: 7je0v8AiBB4

Length: 41min 4sec (2464 seconds)

Published: Mon May 06 2019