HP DV6-7245US Won't Charge

[Topcat]

Tried 3 batteries, all the same.... Wont charge on or off. OS (Windows or Linux) says 'not charging'. BIOS is the latest, batteries are good. OEM charger (also good).... At a bit of a loss.... Kind of a shame, its in mint condition with 16gb RAM in it.

Maybe some of you laptop junkies might have some ideas.

[mon2]

Re: HP DV6-7245US Won't Charge

Review the voltage on each pin of the battery connector.

Specifically interested in the SMBUS (aka I2C) port pin voltages (SCL & SDA) to ground.

Post each measurement for a review.

[Topcat]

Re: HP DV6-7245US Won't Charge

Here's the connector:



8 pins, read from left to right as in the photo:

1 = 3.1v
2 = 3.1v
3 = 3.3v
4 = 3.3v
5 1~1.4 mV
6 = 3.3v
7 = 0
8 = 0

Charge LED is white when batt is out, with batt installed, it flashes back & forth from amber to white; occasionally I can hear a 'ticking' sound from the corner of the unit where the plug is. Laptop functions fine as long as it's plugged in; with or without a batt installed. If I charge the battery in another DV6, it runs fine on batt until the batt dies.

[mon2]

Re: HP DV6-7245US Won't Charge

1) the smbus / I2c line voltages are fine.

2) you may have the usual DCin mosfet failure. Locate the DCin power connector -> nearby should be 2 * DCin mosfets.

a) what are there markings on the topside ? (to determine if N-channel or P-channel)

b) need to check if they are defective or not as follows:

Remove all power / no battery.

Meter in resistance mode -> check the resistance across the mosfet pins:

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. As per above sticky from @Pienov - often the 2nd mosfet gets damaged and leaks causing issues such as this one.

Best to take and post each measurement but if convenient, replace the 2nd of the 2*DCin mosfets for quick testing.

c) The same 2*DCin mosfets will be linked to a local charger IC which will be nearby. Which one is on your board ? Likely the TI (aka BenchmarQ = 'BQ') markings so the above mosfets will then be N-channel style but confirm each detail. From the charger IC information, we can review a typical schematic to debug this case.

d) post any other silk screen markings on your logic board -> found a few schematics in the database with 'DV6' keyword.

[Topcat]

Re: HP DV6-7245US Won't Charge

^
Much appreciated. I'll disassemble it tomorrow.

[Topcat]

Re: HP DV6-7245US Won't Charge

I'm still working on getting this thing apart....it's pissing me off. Palm rest/keyboard is all one piece, hung around the HDMI....and I don't want to break anything (didn't find any missed screws)....so I'll have to consult the google when I have a little more time to figure out what I'm missing...

[Topcat]

Re: HP DV6-7245US Won't Charge

Ok, finally got it....this was a bit of a pain to get apart....but I got it...and dind't break anything.

The motherboard.



Power section:



What appears to be 'PQ3804' (so many numbered components around it) reads a short across the pins indicated with red dots. All neighboring transistors read as they should.

[mon2]

Re: HP DV6-7245US Won't Charge

See attached.

1) to avoid static charge kills, best to place perhaps a piece of cardboard underneath the logic board rather than carpet. ESD bags are even a better choice.

2) what are the topside markings of the referenced parts in the attachment. PQ3804 may be a dual esd diode array for the battery SCL / SDA interface.

Interested to know the square device part number which is probably a 'BQ' (TI) charger IC.

[Topcat]

Re: HP DV6-7245US Won't Charge

See attached.

1) to avoid static charge kills, best to place perhaps a piece of cardboard underneath the logic board rather than carpet. ESD bags are even a better choice.

2) what are the topside markings of the referenced parts in the attachment. PQ3804 may be a dual esd diode array for the battery SCL / SDA interface.

Interested to know the square device part number which is probably a 'BQ' (TI) charger IC.

That is anti-static carpet....I promise, I'm not that careless!! ...but yea, I'll slip an ESD bag under it. Stand by for the numbers.

[mon2]

Re: HP DV6-7245US Won't Charge

Can you also post any additional silk screen markings from your logic board? Perhaps have a schematic in my database or perhaps not but will search for it.

[Topcat]

Re: HP DV6-7245US Won't Charge

The chip, you were correct; BQ738

The transistor is LNW28

[Topcat]

Re: HP DV6-7245US Won't Charge

Can you also post any additional silk screen markings from your logic board? Perhaps have a schematic in my database or perhaps not but will search for it.

Here you go. Unedited.

[mon2]

Re: HP DV6-7245US Won't Charge

May have a hit...see attached.

1) PQ3804 = 2N7002 (SOT-23)

2) PD3802 is on your board - also in the next attachment.

3) PU4001 = BQ24738 charger IC

4) DCin charger mosfets - as per sticky from @Piernov, often the 2nd DCin mosfet gets damaged. Review the voltage on each pin of these 2 * DCin mosfets.

Interested in:

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

voltage readings of each - PU4006 & PU4004 (likely the defective guy).

5) After the above check -> power down -> meter in resistance mode.

Check the resistance across the above 2 x mosfets as per above.

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

PU4004 is of interest. If really keen - replace this mosfet and test again.

These mosfets are N-channel so the gate has to be higher than the voltage it is passing and should be ~25v using the ACDRV pin on the charger IC (BQ).

Confirm it is this voltage to enable the 2 x DCin mosfets.


It is yabba-dabba-doo time at the office. Will continue to monitor the thread over the weekend. Do post your readings.

[Topcat]

Re: HP DV6-7245US Won't Charge

It is yabba-dabba-doo time at the office. Will continue to monitor the thread over the weekend. Do post your readings.

Same here and I'm going to be pretty busy this weekend...but I'll get this done.

[Topcat]

Re: HP DV6-7245US Won't Charge

I haven't forgotten about this, just been crazy busy!!