Power ON / Trigger Section in Desktop Motherboard and Its Problems Solutions

Power ON / Trigger Section in Desktop Motherboard and Its Problems Solution

Power ON / Trigger Section in Desktop Motherboard is used to “ON” the Motherboard by given trigger. It Relative this section components is SIO, PS-ON jumper and ICH.

Ok Condition


When provide trigger or ON Button pressed, the motherboard is ON .it means This section is working.

Faulty Conditions

 Motherboard total dead
 Motherboard Direct ON
 Motherboard Restart again and again
 Motherboard ON but just after few seconds OFF
 Give Command Turn OFF but computer is restart.

Main checking point:

• Motherboard Dead: in this condition First of check Voltage on PS-ON Jumper (3.5v to 5v). if no voltage then check SBV and PS-ON on SIO Chip , It should be present. SBV and PS-ON both present on SIO but no PS-ON check PS-ON near LVR and Components near SIO. components is ok but same condition Heat SIO and Replace.
• Motherboard Direct/ again and again restart: In this condition check LVR near PS-ON Jumper and SIO. It may be Short, and also SIO Problem.
• Motherboard ON but just after few seconds OFF/ Give Command Turn OFF but computer is restart: Check SIO chip and PS-ON Jumper LVR Resistance.

PS-ON- Power Supply ON

SIO- Super input output chip

LVR- Low Value Resistor