HP Elitebook 745 G3 no popwer

[Joztu]

Hi house,

I have an HP elitebook 745 g3 with no power, I've checked the board for shorts but can't find any

3v and 5v aren't present either, 20v is also not present pin ACp and ACn of the charging IC

q1304 has 20v on one end and only 4.7v on the other end, meanwhile on another similar board 20v is present on both sides of q1304

I've reprogrammed the BIOS, changed the charging IC and still no luck with getting the system to turn on


Please i need assistance from everyone who can offer


Board number: TI - 6050A2728001-MB-A03

[mon2]

Would you have schematics? If yes, post them in the schematic forum and link them here.

Review the charger sticky by @Piernov.

Respectively, review the 2 * DCin mosfets. Remove all power. Meter in resistance mode.

Measure the resistance across the mosfet pins and post each measurement here:

source (1-2-3) & drain (5-6-7-8)
source (1-2-3) & gate (4)
gate (4) & drain (5-6-7-8)

Checking for a low resistance in the measurement which means the mosfet is defective.

Next, attach the power adapter and carefully measure the voltage to ground of each mosfet pin and post each measurement here:

source (1-2-3)
gate (4) ; should be ~25 volts to enable the N-channel mosfet - if it is lower, something is wrong / mosfet could be defective and is leaky
drain (5-6-7-8)

[Joztu]

Would you have schematics? If yes, post them in the schematic forum and link them here.

Review the charger sticky by @Piernov.

Respectively, review the 2 * DCin mosfets. Remove all power. Meter in resistance mode.

Measure the resistance across the mosfet pins and post each measurement here:

source (1-2-3) & drain (5-6-7-8)
source (1-2-3) & gate (4)
gate (4) & drain (5-6-7-8)

Checking for a low resistance in the measurement which means the mosfet is defective.

Next, attach the power adapter and carefully measure the voltage to ground of each mosfet pin and post each measurement here:

source (1-2-3)
gate (4) ; should be ~25 volts to enable the N-channel mosfet - if it is lower, something is wrong / mosfet could be defective and is leaky
drain (5-6-7-8)

apologies I didn’t get back earlier, owner didn’t leave it behind

thanks though