Hi everybody! This laptop eat my days in the last week. Initial i buyed a new battery, thinking is a battery issues but is not. The laptop charge fine, turn on fine when is plugged but when unplugg is dead. I think is a mosfet or chip who need to do the switch, but i cant identify him, and for that i need community help, thanks in advance! The mb is FA495-NM-C131-REV-1.0
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Review PQ18 and PQ103 mosfets. Remove all power. Meter in resistance mode. Measure the resistance across this mosfet.
Check:
source (1-2-3) & drain (5-6-7-8)
source (1-2-3) & gate (4)
gate (4) & drain (5-6-7-8)
Testing for a low resistance. Each resistance should be hundreds of k ohms or higher for a normal mosfet.
Post each measurement. No power to the board during these tests.
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I verified, i haved low resistance between source and gate of pq103. After desoldered it, i have low resistance between source and gate of pq18. I changed pq103 with another mosfet. The laptop power led flickering orange/white and dont start with battery connected. After disconnect battery, turned on plugged in. It s possible to both of them be faulty?Comment
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Test the removed mosfets on your work table. Are they still with the low resistance measurement? The in-circuit resistance may be different than out of circuit resistance. Also review PQ102 but note that this is a dual mosfet in a single package but testing method is the same.
Full details on this issue are posted here:
https://www.badcaps.net/forum/troubl...arging-circuitComment
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The ISL88739 & ISL88739AHRZ are a highly versatile combo battery charger
configurable for operating as either a Hybrid Power Boost (HPB)
charger or a Narrow VDC (NVDC) charger, supporting 2-, 3-, or
4-cell batteries. Both configurations allow the battery to work with
the adapter together to supply the system load when it exceeds
the adapter capability, referred to as system Turbo mode. HPB
charger configuration reverse-boosts battery energy to the system
bus to help the adapter provide the system power in Turbo mode.
NVDC charger configuration...11-05-2024, 03:28 PM -
ISL6257HRZ ISL6257HRZ-T Laptop Battery Charger Datasheet
Highly Integrated Narrow VDC Battery Charger for Notebook Computers
The ISL6257HRZ ISL6257HRZ-T is a highly integrated battery charger controller
for Li-Ion/Li-Ion polymer batteries. ISL6257 is designed for
Narrow VDC applications where the system power source is
either the battery pack or the regulated output of the charger.
This makes the max voltage to the system equal to the max
battery voltage instead of the max adapter voltage. Operating
at lower system voltage can improve...11-05-2024, 04:43 PM -
Hello guys, i need help with this problem, I have a NM-D041 mobo, it came with low impedance in 3v linear regulator rail, the cause was a damaged EC controller ITE8227e-192. I ordered a new one and replaced it. This laptop have a different chip for keyboard management and it8227e pins for programming ITE chips are not accesible through keyboard interface, I flashed it using i2c interface pins with vertyanov programmer because laptop was dead and SPI flash didn't have power (only 3v EC) so it couldn't access firmware stored in SPI memory. I read SPI and extracted it8227 firmware from original BIOS... -
I have an RC radio handset(Taranis QX7) which doesn't have internal battery charger which means I had to remove the battery every time I needed to charge it.
So to improve it, I added a 15W USB-C charger board(link) inside and soldered it to the same connector on the PCB where the battery plugs into, great, now I can simply charge it with a USB-C cable.
but the problem I found is that after the radio sat for two weeks without being used the 2S 18650 battery that I'm using was at 4.2V!
So the battery is backfeeding the charger and being drained.
How can I prevent... -
For Badcaps Readers, Please note that I am hopefully going to present this same message to Lenovo to see if they have any insight to the matter as well and figured to share the entirety here for clarification. The System is out of warranty as it is but does have the option to have it extended.
Model Information: T14 Gen 2 (Type 20XK, 20XL) Laptop (ThinkPad) - Type 20XK - Model 20XK0069US
Board: T14 Gen 2 (Type 20XK, 20XL) - Type 20XK.
System Hardware:
Processor: AMD Ryzen 7 PRO 5850U
Memory: 1x 16GB DDR4 3200 (Soldered on Board); 1x Crucial 32GB DDR4...09-08-2025, 10:46 PM
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