Mainboard : CPU power circuit – by lqv77
1 . circuit components :
- the 4 pin 12V Power Supply
- IC fluctuations
- The driver IC
- The power Mosfet
- The coil (around the CPU , to identify specific )
- Input Filter Capacitor 3300MF 16V/1200FF …
- filtering capacitor vCore 6.3V/820MF 3300MF …
2 . How to identify and circuit layout on the motherboard :
– The coil , filter capacitors and MOSFETs around CPU .
– Denmark is conspicuous by arranging events , including links 2, 3 or 4 2 or 3 coils with each coil MOSFET and a wealth of convergence of around CPU socket connector .
– In this circuit , when we have not plugged the CPU ( Pentium 4 or higher ) on the socket will not have the source ( if there is a faulty circuit ) . When you plug the CPU into the power circuit that automatically correct for the CPU needs . To measure the power supply for the CPU test we measure at the foot of the wire . Note in the above line is a filter lane on the roll will be scattered with the coil voltage 12V output filter is a new source of supply for the CPU .
– If the plug does not support the main CPU will have no power at the output vCore . To fix , use at home to check CPU VRM circuit is the best .
3 . General diagram :
4 . Map of the actual circuit principle :
the circuit , using an IC to the pulse and a 0 , 1 , 2 or 3 for the MOSFET driver IC to operate . VCore is the source of supply for the CPU .
5 . Analysis of circuit operation :
– For most motherboards , you just power the motherboard ( not plug anything even more CPU and RAM ) that can then click source . With some cases (especially the motherboard of Intel ) , must try the new CPU is the source size .
– When you click the source was running , the first check for sources and RAM are enough or not ( there will be a specific article regarding this issue .) Then check the CPU power supply has been or not.
– Note: When you plug the CPU is not the source of supply for the CPU will always be zero. If a pressure vessel that is corrupted . When plugged into the CPU if that CPU requirements imposed 1.25V ( This depending on each CPU , refer to the Intel CPU , or attached documents to know the exact level of resources required by each type of CPU ) , the circuit must meet right . That must have at output 1.25V vCore .
6th . Operating the circuit :
– When the Power Good signal ( pin 19 IC RT9241 – first picture ) , pin 16 , 17 will have the pulse signals PWM1 , PWM2 enable the driver IC ( pin IC RT9602 1.2 ) pulse at Pin 4 driver , 12 , 7 , 9 -interrupt controller of the MOSFET to create a major source of vCore .
– the main source of supply for the CPU vCore will . Then , the CPU will respond to the pin 1 , 2 , 3 , 4 , 5 ( IC RT9241 ) to determine levels of resource requirements . Respectively as the table below . If this signal is not received immediately stop the pulse -level PWM voltage News will not be open at the vCore .
7 . IC datasheet of some things around , driver power supplies for CPU :
- ADP3110 – ADP3180 – ADP3181 – ADP3188 – ADP3163 – ADP3168 – ADP3198 – ADP3416 – ADP3418 – ADP3421 –
- FAN5019 – FAN5090
- ISL6316 – ISL6556 – ISL6561 – ISL6566
- RT9241 – RT9245 – RT9600 – RT9603 – RT9602 –
8 . Common Errors :
- Touching the CPU power MOSFETs lead to loss . will cause severe damage to both the source level . Easy to see this MOSFET will heat very quickly after power up until a few minutes . Or maybe by 2 feet by removing from G and S mainboard.
- Death of IC fluctuations , the impulse , the driver . This error is common, and the only way change only.
- The filter capacitors were consistent source or cause dry cocoons CPU . Be careful when replacing the capacitor . It replaced the capacitor is equal to the numbers from larger and have the same output filter capacitor for the CPU .
- Remove all major components in the short- circuit power is still present . Due to the chipset North convolution . Do some motherboards , chip shared resource for North CPU vCore level .
9 . Ordering check :
- VCore internal source resistance . ( Often touching IC MOSFET or agitation )
- each MOSFET to remove the measure to detect slow or ri.
- Contact from the foot of G IC MOSFET fluctuations . ( open circuit or lead to loss of contact )
- VCC to the IC source fluctuations . ( Often, this power outage due to broken fuse or touch dead IC )
Share:
English 
العربية