Laptop Motherboard No Power - Troubleshooting Short circuit - Fixed!!-Part 1

so let's connect the power adapter and then check the 3 volt 5 volt circuit let's put the black probe of the multimeter in the ground and check these two inductors here we have 5 volts and in the second inductor 3.3 volts if we check the component next to inductor we have 3.3 volt into electronic capacitor and also into this point or the part the same for this channel I have 5 volt in the inductor 5 volts into electronic capacitor and of course we should find 5 volts into this point or the path means this circuit is a serviceable circuit let's connect to power adapter oops we have a problem we have a short circuit here thank you foreign let's do it again 100 this motherboard is shorted we have a short circuit here once we connect to plug the LEDs turned off means we have a short circuit I in this video I'm going to teach you how to track voltages in a deed motherboard using the multimeter and the circuit diagram I'm going also to teach you how to find a short circuit and solve it so let's get started so because the three volt and five volt circuit is the responsible for generating the primary voltages for Google motherboard we get a first check this circuit so as you can see here we have three volts and five volt channels so let's connect the adapter and then check whether we have 3 volt and 5 volt in this motherboard by the way this motherboard is a deal motherboard I'm going to show you how to repair it step by step so of course we should set the multimeter to do DC voltage as you can see DC voltage of course we're gonna select 20 volts because the adapter generate 19 volts so let's select 20 volts in the multimeter and let's check the two inductors here as you can see we have ground everywhere in the motherboard so let's put the black Probe on the ground and then check using the read probe of the multimeter these two inductors so let's check the part we should get 5 volt basically this is the five volt Channel as you can see the multimeter will get zero volts means the 5 volt is missing so let's check right now to 3.3 volt Channel so let's check the inductor nothing in the multimeter as you can see we get zero volt into millimeter means also the 3.3 volt is missing what should we do right now we should confirm if the 19 volt is received by the motherboard or not so let's check this inductor basically this is the input as you can see we get 19 volt we have 19 volt so because we have 19 volt normally we should get here three volt and 5 volt because the 3 volt and 5 volt voltages are always present in the motherboard once you connect to adapter without powering on the motherboard [Music] so now if we go to the schematic as you can see this is the import voltage the 19 volts for the three volt circuit as you can see and here also for the five volt channel here we have to input voltage the net involt as you can see we have plus v but so as you can see we have two serum capacitor as you can see C10 47 and Theta for a sex okay we should find 19 volt in this capacitors and also in desmosphate Q10 zero nine the drain of the small switch should receive 19 volts the same for three volts as you can see Channel we should find 19 volt in This Server capacitor c1062 and in the drain of the small Street q1023 so let's see in the motherboard so as you can see here this is the 5 volt Channel and we have inductor L3 and we have the part part one this is the electronic capacitor c21 and here we have seven capacitor C 22. so in the back of this circuit we have the input component here we have two semi-capacitors as you can see C 10 47 and c1046 and we have q1009 normally if we check this set of capacitors in this side and the drain of this mosfet we should get 19 volt okay so this is the search for this mosfet gate as you can see and this is the drain four pins connected together so let's connect the adapter and let's check these two serving capacitor here we have zero volts normally we should find 19 volt so let's check the drain for this mosfet normally we should get 90 involved the same we have zero volt so the three volt five volt circuit does not receive the 19 volt so we should track this native Vault from A to Z until we find the failed component so now I'm going to show you how to track the Neti Vault from the power jack until the three volt Firefall circuit using the multimeter and the circuit diagram so this is the circuit diagram as you can see here we have the DC jack as you can see okay the native voltage goes directly pass through the serum capacitors and then goes to q1002 and then goes directly until we get here plus V part this plus v but will be distributed to the whole motherboard to all circuit in the motherboard basically this plus v bot is missing we should find the field component so let's connect the adapter once again so the adapter is inserted is connected to the motherboard so we're gonna put of course the black prop of the multimeter and the ground everywhere in the motherboard so let's check this serum capacitor as you can see we have 90 involved let's check the second one I have a 19 volt as you can see here we have inductor we should get 90 volt in both sides as you can see we get 19 volts in both sides exactly as we have in the schematic now if we go to this mosfit Q102 as you can see in the schematic we should get 19 volt here in research in three pins and of course let's check the gate we have the control signal this is the control segment so we have the 1914 Industries and the control signal we should get 19 volt into either side in the drain through this check UPS we have zero volts means here we have the problem this mosfet is failed or we have a short circuit in this motherboard we have two options maybe this mosfet is failed or we have a short circuit into other side of mosfet so let's check it out [Music] so as you can see I didn't find the same mosfet with the same reference and I make it just a bridge as you can see using a wire between the drain and two Source just in order to put trap shoots and to find the problem so here we have the adapter as you can see we have this we should you should always use this kind of adapter in order to detect if you have a short circuit or not so let's connect adapter Ops do LEDs are turned off as you can see so let's do it again as you can see the two LEDs are on CE we connect to adapter do a light and switch it off means we have a short circuit in this motherboard this is a well-handed short circuit it is motherboard because the LEDs are switched off once we connect to adapter so I'm going to show you how to find the short circuit and how to solve it so this is basically the schematic so the short circuit is in this side as you can see the short circuit is in the side of the motherboard because once we make a bridge between source and drain we'll get a short circuit so we should check all this components so I'm going to show you how to find the short circuit step by step [Music] thank you foreign [Music]

Channel: Electronics Repair Basics_ERB

Views: 232,486

Keywords: Laptop Motherboard Repair, laptop motherboard repair courses, laptop motherboard repair tutorial, laptop motherboard repair step by step, short circuit explained, short circuit laptop, short circuit motherboard, short circuit motherboard fix, find short circuit motherboard, repair short circuit motherboard, dead motherboard repair laptop, how to fix short circuit computer, how to fix short circuit board, how to test mosfet using multimeter, symptoms, electronic repair school

Id: qv8qcpRyYQU

Length: 11min 41sec (701 seconds)

Published: Wed Mar 29 2023