FrozenHaxor
Badcaps Veteran
Last Activity: 12-03-2025, 07:34 PM
Joined: 06-02-2015
Location: Warsaw
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I put the laptop together already, but the gate drive voltage from ACDRV was a nice 24.7V as it should be, ACOK at correct steady 3.3V, ACDET at 2.7V.... -
Case closed, replaced faulty BQ chip, it was not driving the PQ100's gate at all. Replaced PQ100 preemptively as well if it turned out to be the cause of BQ's failure. Power rail sequence is now correct. Thanks for the support.Last edited by FrozenHaxor; 10-17-2025, 02:24 PM.Leave a comment:
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ACOK can't be 6V, it's pulled up to the +3VL rail only. It goes to 3.3V when I bypass the MOSFET and boot the board.
There is no PR112 or PR111 populated....Last edited by FrozenHaxor; 10-17-2025, 01:38 PM.Leave a comment:
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There is no short. When I bypass PQ100 MOSFET (connect drain and source together) I get the laptop to fully power up....Leave a comment:
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PQ101 is okay
PR100 is good (0.03Ohm)
PU100 pin 3 0V
PU100 pin 4 0V
PU100 pin 5 0V...Leave a comment:
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Lenovo Ideapad 3 15IIL05 NM-D031 +3VALW missing
Hello,
Having an issue troubleshooting this board, it takes no current. PQ100 MOSFET gets 0V on the gate and does not open, when I short it out the laptop powers up. There is 0V on ACDRV from BQ24780, 0V on ACOK.
Now for the fun part, ACOK is pulled up to 3VALW rail, when I short out the PQ100 and power up the laptop, ACOK jumps up to correct 3.3V, as soon as I remove the short across the MOSFET it goes fully dead again. Now my issue is that according to schematic this is a circular logic, I can't have +3VALW without getting power to the PU1101 SY8386BRHC, but I can't... -
SOT23 component identification
Hello, I have two identical circuits and one has a component with a hole in it, it is some sort of MOSFET driver, as two gates of large MOSFETs are connected to the lower right pin of it, I'd rather avoid guesswork if positive identification is possible.
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Good insight, I only traced one current resistor to the ISL but didn't do it with the BQ as there are two of them, turns out there is internal trace broken to one sense pin, ran a wire and the readings are normal, charging came back.
Thank you for the help....Leave a comment:
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ACDET = 2.6V
REGN = 6V
ACN = 18.7V
ACP = 19.5V
ACDRV = 25.4V
The laptop works and powers on, just isn't charging on this BQ IC, charges fine on the ISL when plugged to USB-C though....Leave a comment:
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Asus FA507 not charging the battery on main supply, only charing on USB-C.
Hello, I have DA0NJSMBAD0 board that has dual charge ICs, one of them is BQ24800 and the other is ISL8238CH
Now this is a very peculiar design, they're using the BQ to charge from the main 240W power brick path, and the ISL to charge from USB-C PD port.
The ISL side works fine, but the BQ side does not. Battery is good.
I have swapped it for BQ4780S as it's essentially an older version of the chip and there was no change. I get 19V VCC to the BQ, and the ACOK is 3.15V
Any insights into what this could be?... -
Very doubtful they did that, inspect the board. Lenovo are notoriously hard to do this on due to the black epoxy underfill used on BGA components. BGA desolering in this case usually results in delaminated board and ripped pads along with lifted traces....Leave a comment:
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No, the KBC itself is programmable with embedded flash....Leave a comment:
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What do you mean exactly? You have erased the KBC then powered it on without any contents? On some Lenovo boards there will be an automatic KBC programming taking place using EC region from main bios flash, but I only know of that on brand new KBC chips that have certain factory flag still set which goes away upon first programming.
The board will absolutely not start in any way shape or form and certainly not allow you to enter BIOS settings with an empty KBC chip....Leave a comment:
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Try connecting external display through HDMI and disconnect eDP connector, if it's routed through the CPU and not the GPU directly, you'll be able to enter BIOS and set the graphics to UMA only.
Usually I would replace the dead GPU chip, but Lenovo is a menace and uses black underfill glue that ruins the board when trying to desolder the BGA chips. It's possible to get the glue debonded but it's not worth the effort, better to run that board in UMA or just replace it....Leave a comment:
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Yes, documented corrosion spots then put it through ultrasonics, board is spotless....Leave a comment:
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Fixed with DMI information preserved. Main + extracted EC file....Leave a comment:
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It's not a BIOS issue, your GPU core is dead....Leave a comment:
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What is more interesting is that when I take off the ground probe, then touch +1.0VALW_EN with my other probe, suddenly the power draw jumps up from 8 to 17mA and +1.0VALW_EN becomes present:
+1.0VALW_EN (PCH_PWR_EN) = 2.34V
+1.0VALW on PL500 = 1V
Must be some static charge effect that latches the signal up.Leave a comment:
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Resistance to ground on PL500 = 47.5 Ohm
+1.0VALW_EN (PCH_PWR_EN) = 0V
+2.5V_DDR_EN = 0V
+1.8VALW_L_EN = 0V
+1.05VGS_B_EN = 0V
VDDQ_EN = 0V
VTT_EN = 3.16V
PMIC_EN = 2.9V...Leave a comment:
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Schematics and boardview files: https://www.badcaps.net/forum/troubl...82#post1519682...Leave a comment:
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