Quanta 0P5 (DA0P5HMB8E0-Rev E) Missing ACDRV

[ResoluteHawk]

I have an HP 15-DY laptop in because the battery is not charging.

If I use a charged battery, the laptop powers on but the battery will not charge, however the orange charge light does turn on. The laptop loses power as soon as I disconnect the battery.

I've replaced the BQ247 chip with a known working one and I get the same issue and the same measurements.

Measurements are as follows:

BQ728 IC
VCC (Pin 20) => 19V
CMSRC (Pin 3) => 0.8V (This is a problem but I can't figure out what's causing the low voltage)
ACDRV (Pin 4) => 0.8V (This is also a problem....I'm supposed to be getting 25V here)
ACOK (Pin 5) => 2.9V
ACDET (Pin 6) => 2V
REGN (Pin 16) => 6V

PQ1001 Drain to Source => 2.7M Ohms
PQ1002 Drain to Source => 238K Ohms
PR1020 => 4K Ohms
ACDRV (PR1020) to GND => 50K Ohms
CMSRC to GND => 1.92M Ohms
+VAD (PR1021) to Source of PQ1001 => Good Continuity
+VAD to wherever +VAD is present => Good Continuity
PR1021 => 4K Ohms
PR1024 (ACDET0) => 433K Ohm

I can't figure out what is causing this issue. It is probably something simple but I can't see it. Thanks to anybody who can help.

Boardview and schematic are available on this forum by searching the board number and revision that are in the thread title.

EDIT: Forgot to include measurements for PQ1001 and PQ1002.

[mon2]

ACDET (Pin 6) => 2V

This is too low. Check the resistor based voltage divider circuit that will use the adapter voltage to lower it to a safe voltage. This voltage should be 2v4 or higher to gauge that the power adapter is good to power the board.

[ResoluteHawk]

This person had the exact same issue that I do now, but I do not have the same fix as they did.

In their post, they state that after repairing the trace break, the board worked fine. Their board worked but they also said ACDET was 1.9V.

In any case, if I am reading the schematic correctly, PR1024 is where the AC voltage gets stepped down. It is 19.5V on one side and 2V on the other.

Should I change PR1024 to a 330K Ohm resistor like they did?

Also how do you know that ACDET has to be 2.4V or higher? Apologies if this is a simple question but I don't understand.

[ResoluteHawk]

Swapped out PR1024 with a 320K Ohm resistor and now 2.6V is present on ACDET, but still no charge light and input mosfets are still off.

0.8V is still present at the Source on PQ1001 and PQ1002.

[mon2]

From the datasheet for the charger IC. While this exact part is unique and not the datasheet is not public, you can check other available parts from Texas Instruments.

The charger ic = BQ24728HRGRR and from my database, found the following.

Remove all power. Meter in resistance mode.

Measure the resistance of PR1024.

Measure the resistance of PR66.

Use an online resistor based voltage divider and insert the values you see from the schematic - the Digikey one is a good one to use.

With 19v as the source (power adapter) and R1 = PR1024; R2 = PR66. In summary, if all is well, the ACDET should be 2v4 or higher with a 19v adapter.

[ResoluteHawk]

Sorry; see my post above. I think I posted that while you were typing your reply. Woops.

Anyway, PR66 is not present on my board. There's empty factory solder pads.

PR1024 measured 433K Ohms before I swapped it with a 320K Ohm resistor to get the 2.6V on ACDET.

[mon2]

Yes. Good. Remove all power. Measure the resistance to ground of ACN / ACP on this same charger IC. Checking to see if the main power is shorted or not.

For the 2 x DCin mosfets, test each as follows (in resistance mode):

source / drain
source / gate
gate / drain

PQ1002 may be defective from the shared resistance.

[ResoluteHawk]

ACN to ACP is continuous. Main power rail is not shorted

PQ1001
Drain to Source => 2.7M Ohms
Gate to Source => 435K Ohms
Gate to Drain => 2.3M Ohms

PQ1002
Drain to Source => 238K Ohms
Gate to Source => 230K Ohms
Gate to Drain => 3K Ohms (This seems really low)

Removed PQ1002 and measured for ACDRV. It's present now.

Can't believe it was that simple. All I have to do is replace this little prick lol.

[mon2]

Yes. This case is textbook from the sticky on charger ICs above by piernov.

[Sametbey]

can you control this post ,

https://www.badcaps.net/forum/troubl...creen-bq24780s


asus battery , orange - BatterryPress

BattPress to Ground, out Voltage ,