CPU Vcore " VRM" Section Explained

hello everyone so today i want to talk about the cbu vrm section okay what does cbu vrm section do it generates the cbu v core voltage when all other when all other voltages are okay all powers are okay then the cbu vcore voltage will be generated by the vrm section the vrm chip works on 5 volts and it requires an enable signal in order for it to start generating the vcore voltage this enable signal is called vr on signal and we talked about this in the previous video the vr on signal comes from the super i o let's draw the super i o let's say here we have super io or kbc let's see okay the kbc will generate this signal and will send it to the vrm chip or the cbu power supply controller sometimes it's called so let's draw here this chip let's call it vrm the cbu will get that kpc i mean will generate a signal called vr on signal and we'll send it to the vrm chip the vrm chip will start to check two things first it will check whether the cpu is present so here is the cbu cpu okay so there is a pin called v sense okay so this v sense is connected to the vrm chip the vrm chip will check the cbu if it is there or not via this bin vsan spin and also it will check the cbu whether it is hot or not there is a sensor bin called ntc let's draw it here and tc pin this is a temperature sensor within the cpu so the vrm chip will also check the ntc pin of the cpu okay if these two are good the v sense is good and tc is good then the vrm will start triggering the mosfets that drives the cbuv core so if example for example we have mosfet here and the mosfet here for phase one both of these are connected to the cpu this will be driven by the vrm and this will be driven by the vrm okay so these mosfets have 19 volts in here and this one is connected to ground g and d okay the output of these two is connected to the cpu through a coil okay so if phase two we have also here 19 volts in here let's throw it this way and here we have a coil and also these two most of it gates are driven by the vrm chip okay so if these two of or i mean if the cbu v core is good have been generated by the vrm chip the vr m chip will send a signal back to the kvc it's called we talked about this in the previous video it's called v-gate or sometimes they call it imvp power good or sometimes vrm power good all are the same so this vrm chip or cbu power controller will send this signal back to the kbc say saying to the kvc that the v core is good okay there is also another set of mosfets two of them 19 volts is connected to the first and to the second one is connected to ground and also these two are driven by the vrm chip and the output of these two will go to the cpu but to the embedded graphics so this is called gfx we call gfx score okay and also this is this passes through a coil so how does this work again the kbc first will send the vr on signal to the vrm this vr on signal is enable signal for the vcore when all bowers in the motherboard is good the last thing to work is the cpu so the vron chip will be produced by the kbc and will be sent to the vrm chip the vrm chip will check the cpu whether it is there or not via the vsense bin and it will check this cpu temperature via the ntc bin okay if all of that are okay then this vrm chip will start driving these mosfets all of these if the voltage is good and the cpu started to run then the vrm chip will send back a signal to the kbc called v-gate or we said it's sometimes called imvp power good or vrm power good this is how the vrm section work i want to draw here a flowchart if you have the cbu vcore is not coming so let's say cpu core not coming or not on let's say first thing you you need to check is vr on signal okay is it coming from the kvc if not check the super i o and [Music] the previous voltages the voltages that appear to the motherboard before the v core should appear so if not say let's say no check all voltages and check kbc okay if yes then what you need to do next check the five volts so this vr run chip i mentioned it i mentioned it but i forget to draw it here so this vrm chip works on 5 volts 5 volts so ok if yes you do have this vr on gate i mean vr on signal from the kvc then check do you have the 5 volts coming to the vrv arm five volts good do you have five volts if no check let's say no check why you don't have five volts why no 5 volts if yes then check your mosfets these mosfets if you have this 5 volts if you have the vrn signal and you have the 5 volts and you still didn't get the v cv uv core then check the mosfets check mosfets okay i hope this is clear if the mosfets are good then the last thing you need to do is to replace your cbu cpu so this is how you check the vrm section or why don't you have the cpu running the cpu is not running the very first thing you need to check is the vr on signal is it coming from the cb from the kvc if it is there then check do you have 5 volts to the vrm chip if that 5 volts are ok then check the mosfets that drives the v core and if all mosfets are ok then replace your cpu which is not an easy job okay so i just want to highlight something on my one of my previous video when i talked about the charging section battery charging section because one guy at the comments said what does that phase been if we if exam if for example we have here the charging ic i see there is wind call phase this pin goes to two mosfets one is called high mosfet and is connected to 19 volts and one is low mosfet and it's connected to ground both the output of these two mosfets are connected together to the phase bin of the charging ic both of these gate mosfet gates are driven by this ic okay he was asking what is this bin is is used for first these two mosfets are used to charge the battery okay through a coil this is a coil these two mosfets are used to charge the battery and this pin the phase bin is used to monitor to monitor this charging voltage and the oscillation of these two mosfets these two mosfets are driven by a signal called pwm pulse width modulation and these two mosfets forms a voltage divider so there is no 19 volts go this way to the battery i think it's around 11 volts to 14 volts i think okay so these two mosfets are used as a voltage divider and it's their gates are driven by a pwm signal so because it's a bwm signal there will be an oscillation in the output voltage so this spin the phase is used to monitor this voltage and the oscillation on this line to the battery okay so i hope this will be as good information for someone to diagnose his laptop or motherboard if you do like my video please share like and subscribe thank you for watching and see you in another video

Channel: FixTronics

Views: 18,655

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Id: BZnoWbvDlmo

Length: 17min 3sec (1023 seconds)

Published: Sun Nov 07 2021