HP431 don't trigger, common failing share

A HP431 laptop, the motherboard is same with CQ43, don’t trigger, don’t work. Insert the power adapter and connect the power supply, 0.022A standby current, Press the power button, the power led lights, But the current is very small 0.022-0.024A, almost have not big change. So think the Embed Controller chip works, but the chipset ( BD82HM65 ) does not trigger, because the embed controller control the power led and trigger led, and the current has a very small change after trigger.

Re-write the embed controller bios, the same fault yet. Find the schematic diagram (same with CQ43), check EC_PWRBTN# (from EC to HM65) first. .... read more