Hi [USER="295753"]mon2[/USER], I was out of town for the summer and had to leave this repair sitting on my desk for a few months. I'm back now and I've tied 3.3V to ILIM by shorting PR8913. The battery is still not charging when the charger is plugged, and the charging coil on the motherboard seems to be sitting at the current battery voltage and not increasing as expected to start charging the battery.
Is there anything else I can check as far as prerequisites for charging go?mon2...
cope
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Last Activity: 12-17-2024, 02:41 PM
Joined: 05-13-2024
Location: Arkansas
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I will work on testing as you mentioned.
I'm learning a ton here so I have lots of questions, but I know you're busy helping lots of people so telling me you are too busy to answer is also fine.
It just clicked that the circuit we are looking at is a voltage divider (and the same you were testing with the calculator you sent earlier). Its purpose is to step down +3.3V to the ILIM voltage required.
In the calculator diagram:
PR8913 is R1
PR8914 is R2
Vout is the line going to ILIM (and the other Vout would be GND? I'm less sure about that...Leave a comment:
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Hmm, just an observation but the schematic rates PR8913 at 120kohms but it measures 89kohms. Is that a significant enough difference to cause an issue?
Also PR8914 schematic value is 68kohms but it measures 57.6 kohms, less of a difference but just so you have the information.
[ATTACH=JSON]{"data-align":"none","data-size":"full","title":"image.png","data-attachmentid":3272720}[/ATTACH]Hmm, just an observation but the schematic rates PR8913 at 120kohms but it measures 89kohms. Is that a significant...Leave a comment:
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Hmm, I've never done that before so I may need a little help so I don't goof something up. I have a resistor that separates the ILIM circuit from +3VA, should I just bridge that? Attaching a zoomed in BV with the resistor circled and its location relative to the ILIM pin.
[ATTACH=JSON]{"data-align":"none","data-size":"full","title":"image.png","data-attachmentid":3272692}[/ATTACH]Hmm, I've never done that before so I may need a little help so I don't goof something up. I have a resistor that separates the ILIM...Leave a comment:
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mon2[USER="295753"]mon2[/USER] While I had it powered down I touched up the solder on pins 22-28 of the BQ chip with an iron (I'm thinking maybe I didn't do a great...Leave a comment:
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mon2[USER="295753"]mon2[/USER] Sorry, did you mean the connector on the motherboard or on the battery for the diode test of data/clk lines?Leave a comment:
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I was seeing a boost to about 16.8V-17.2V when the adapter was plugged in while charging yesterday. This was when the battery was outputting about 15V to the coil (at 7% charge). These numbers are from memory and may be a bit rough because I've had to remember a lot of numbers lately.
I am charging with my bench supply limits set at 17V, 0.5 amps and the battery seems to pull .5 amps at 15.5V.
This is my second Amazon battery, the last one had a blown fuse and would not take a charge with my bench supply. I went with a different seller this time and it seemed to be...Leave a comment:
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Yes, I ran the laptop on battery only, planning to start charging it again at 10%. But, I got distracted by work and it was shut off when I looked back over. When I looked away it was at ~13%. Plugged it in and started back up and the level showed 5%.
Let me see what information windows has about it, I assume in device manager on the battery itself?...Leave a comment:
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Reading 1.182V on pin 1 of PC8911 which is P_CHG_ILIM_10 on the BV/schematic (I am nervous about measuring the pin directly with a charged board, I blew another cap a month back by bridging it to ground on accident).Leave a comment:
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mon2[USER="295753"]mon2[/USER] Are you aware of any reason that a low battery voltage would inhibit charging? After allowing it to drain and plugging it back in it is not charging and the battery is remaining at 6%.
I can charge the battery with my bench supply stillLeave a comment:
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This time it seems like it must have been a bad connection between the SRN pin and the motherboard when I resoldered it. Cleaning up the solder joints has thus far solved the issue and the laptop is fully functional.
Thanks to everyone for their help!...Leave a comment:
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I looked closely at those pins and saw copper, so I ran a hot iron down that side to clean up the joints and the battery is charging now! 25% and climbing. Here's hoping it stops trying at 100%!...Leave a comment:
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mon2[USER="295753"]mon2[/USER] OK, on the chip itself I am getting 0L, but there's some flux from the resolder that might be getting in the way of the probes...Leave a comment:
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All charging IC voltages are written on the attached schematic picture above next to each pin in white text. But for those pins:
ACOK - 5.95V
ACDET - 2.7V
REGN - 6.01V
SDA - 3.24V
SCL - 3.25V
VCC - 19.63V
For ACP/ACN resistance I measured resistance across PC8902. -> 1.4 ohms
DC in voltage (PQ8901/PQ8902) has been ~25V on the gates and ~19.8V on source/drain (not near the laptop currently so this is ballpark, I can get exact numbers). It does run fine on the adapter (gets into windows, cpu doesn't throttle, GPU is recognized,...Leave a comment:
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I will look into posting them in the schematic forum, thank you. (EDIT: I see SMDFlea took care of this for me , thank you!)
The OS does detect the battery and shows the current battery level (6%), it also says it is charging but it does not actually charge.
I have measured all voltages on the BQ and written the voltages on the schematic. Attached to this message.
Pin 15 is 0V
This is with the battery connected and the adapter plugged in.
My factory battery has a blown fuse so the battery I have in is a replacement from Amazon that...Leave a comment:
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Battery not charging in ASUS G532LWS Motherboard -> BQ24780S
Hi everyone,
I have been working on a no power issue with my personal ASUS gaming laptop. It went dead a few months ago.
Some history:
Since then, I've found a blown mosfet on the GPU line which I replaced. It started up without a battery, then when I added the battery back it wouldn't start up again.
As a result, there were some blown components around the BQ chip. (The BQ chip itself - BQ24780S, the low side battery mosfet (shorted), and a resistor -> all replaced)
Now, with a new battery the system will start up and run off...
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