HP DM1 Laptop Doesn’t Boot, +VCC_CORE Voltage Missing

A HP laptop doesn’t boot, press power button, the current 0.35A stopped, According to experience, doubt power supply for cpu problem. So test +VCC_CORE (PL13), found +VCC_CORE voltage missing. Observe carefully, there is a small hole on the lower mosfet PQ26, it was damaged. Removed PQ26, test the resistance between PL13 inductor and gnd, the value is normal.

So, replace a new PQ26, connect power and boot again, the current still is 0.35A and stopped. Touch power ic RT8165B, very hot, suspected it was damaged, so replace a new RT8165B. Boot again, the current 0.20A stopped, +VCC_CORE voltage missing, yet. Take the schematic diagram, test +VIN, VCC, PVCC, EN, etc,...read more 

ASUS X43B Laptop Doesn’t Trigger, EC Doesn’t Reset

A asus x43b notebook, doesn’t boot, connect power adapter, the current 0.005A, standby 3V, 5V voltages are normal. When press the power button, the laptop doesn’t trigger, the current doesn’t change. So check EC’s working conditions first, the EC chip is KB930QF A1.

So check power, clk, reset singal, found 37-Pin ECRST# singal voltage is 0.24V only, it isn’t normal. +3VALW is normal, and R1605 plus C1533 are RC Time delay circuit, to 37-Pin reset EC.  read more , By the way, In order to thank for every new and old customers and friends, offer 10% off from November 16th to November 30.

TPS51621 QFN-40 Power IC

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TPS51611 QFN-32 Power IC

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TPS51610 QFN-32 Power IC

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TPS51511 QFN-20 Power IC

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TPS51461 QFN-24 Power IC

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