Hp 640 G2 pluggged in but not charging

[bembeno]

when connect the charger it looks like charging until 2 seconds then the charging logo stop and become plugged in not charging the same charging value i tried another charger and another battarey
what is the volts i should found on battarey connector

[mon2]

Re: Hp 640 G2 pluggged in but not charging

What are the markings on the logic board ?

Link or post the schematic if available on this forum.

Are you using the official power adapter for this laptop ?

Are the batteries known good units ?

Can you read the battery charge cycles, details of the battery pack in Windows?

[mon2]

Re: Hp 640 G2 pluggged in but not charging

I don't think the schematic is available so...

power down -> review the logic board -> locate the DCin connector.

Review the usual 2 x DCin mosfets near this connector. What are the markings on these parts ?

Near these parts will be the charger IC with 'BQ' or similar markings.

What are the markings on the charger IC ?

Often the fault you have raised are linked to the DCin mosfets. We need confirm if they are defective or not using resistance checks.

With no power -> meter in resistance mode -> check the resistance of each mosfet as follows:

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

post each measurement and the scale used on your meter for these tests. If the resistance is low, the mosfet is defective and must be replaced.

There is a possibility that the host logic board is unable to detect the battery which is linked to the SDA & SCL lines on the battery connector. We need to check the voltage on these pins. If the voltage is low, then the I2C interface (SDA & SCL) may be defective so the charger IC gives up on charging.

Start with the mosfet review.

PS: Post clear pictures if in doubt of the logic board details. Most of these logic boards are designed in the same way..

[bembeno]

Re: Hp 640 G2 pluggged in but not charging

the charging ic nomber is BQ 24780