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FrozenHaxor
Badcaps Veteran
Last Activity: 04-23-2025, 04:16 PM
Joined: 06-02-2015
Location: Warsaw
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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.... -
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.
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I have swapped it for BQ4780S as it's essentially an older version of the chip and there... -
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: [url]https://www.badcaps.net/forum/troubleshooting-hardware-devices-and-electronics-theory/troubleshooting-laptops-tablets-and-mobile-devices/schematic-requests-only/71085-ideapad-320-15ikb-schematic?p=1519682#post1519682[/url]https://Schematics and boardview fil...t1519682[/url]...Leave a comment:
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Lenovo ideapad 520, NM-B452 not powering up
Hey, I'm repairing a board from liquid damaged laptop, managed to get 5V and 3.3V rails up, some passives were corroded away. Only problem right now is no reaction to power button, there is no PCH_PWR_EN signal, DPWROK_EC is 2.5V, +1.0VALW is missing. Replaced KBC with brand new one, reprogrammed. No change. Any ideas? Schematic and boardview are available, attached them at the bottom. Boardview file can be opened by "BoardViewer" software.
Please don't mind the damage near UC4, it was caused by liquid damage and there is battery connector on the other side,... -
Re: Yamaha RX-A3010 working, no sound output
Don't bother with the chips, there aren't any good ones available. They're either failed reballed ones or just straight up fakes, and pretty much all the available boards if you can find any will have this fault sooner than later....Leave a comment:
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Re: lenovo y530 dead ite replaced - problems
It's precisely that, they put lots of scrapped boards in a steel tumbler with holes then heat the whole thing with flames, the chips fall off to a bottom pan, they clean them up later and resell as new or used, tested.
Anything "used, tested" from China means you get to test it when you use it. Avoid like the plague....Leave a comment:
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Dell Precision 7710 BIOS Request
Hello,
Attached is the original BIOS dump. Machine blinks 2 orange 1 white ("CPU failure"), much appreciated if somebody could get me a working copy for a test. Service Tag is 2MR9NC2.
Board number is LA-C551P Rev. 3.0(A02)
Thanks again....Last edited by FrozenHaxor; 03-17-2023, 12:31 PM.Leave a comment:
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Re: Aspire E1-530 black screen .
I find that rather hard to believe.
Whats the temperature on PCH when laptop attempts to turn on?...Leave a comment:
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Re: Dell Latitude 14 rugged 5404 - half dead
What about the other rails? 3.3V, Vcore, Vram? Is heatsink getting hot?
When you programmed the chips did they pass read verification against master file?Leave a comment:
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