Dear gentlemen., today working on a Samsung Galaxy NP750XDA Laptop (NB3586-NB3587_PCBN_MB_V5), not charging battery. The laptop came with a dead battery & upon testing the battery Ouput coil getting around 6v, assuming that the battery circuit is ok & only the battery has to be replaced. I ordered a new battery, received & installed it but still same, NOT CHARGING. In the start, on the battery + pin I get 17v which is perfect for a 15.4V battery & then the volts drops down to 6v approx & does not charge or work on the battery & the charge LED comes on & then off. I checked each & every MOSFET in this battery circuit, all are good & no shorts at all. The charging chip is BQ25700A, (VCC Pin 1 ,2,3 20v, REGN Pin 6v, VDDA approx 6v, Pin 4 CHRG_OK 3.2V ). All the main volts to the chip seem to be ok. No schematics available for this model. Can anybody help me in this repairs. Thanks in advance
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Hey
Meter in resistance mode. Measure the full path resistance between pins SRN & SRP (pins 19 & 20) on the charger IC. Compare these values against the reference values in their datasheet or another motherboard schematic. If the values are out of range, the charger IC will sense there is a fault and halt the charging process.
Expecting this measurement to be ~20R ohms - taken from the EVM schematic from Texas Instruments for this device (
Post the measurement.
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Thanks mon2 for the rescue. I will do the measurements tomorrow & inform you. In the meantime, i.e this afternoon, I took out a good BQ25700A from a Lenovo motherboard NM-B741, this board uses the same BQ25700A chip for charging the battery, no chance, still the same. I will check the resistance between pins SRN & SRP (pins 19 & 20), but I sure it will be less than 10ohms as there is a current resistor in parallel. I checked this resistor before & it was fine, but will surely confirm it tomorrow. ThanksLast edited by mferna14; Yesterday, 08:19 PM.Comment
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My question pertains to understanding the control circuity inside a Dell PT434 type battery used in Dell E6400, E6410 and other Dell notebooks?
Does anyone have a circuit diagram for the inside of a Dell PT434 battery and/or a description of how the control lines work to control this battery?
My reason for asking is I have a battery which I cannot get to charge beyond 1% in a Dell E6410 or E6400.
The LED bar graph charge indicator on the battery shows one LED lighted when the info button is pressed.
I have tried multiple different Dell power adapters. My Dell... -
Hi all
We have in a HP ProBook 445 G8 laptop with AMD Ryzen 7 CPU. When power is connected the power LED light blinks 5 times then stops. Normally HP laptops will blink this LED 10 times as it does a self test when the AC adaptor is inserted. So there must be some sort of short somewhere.
The battery doesn't charge, and is erratic on the MM voltage. Bench PSU LED pulsates when the battery is connected also. So the fault must be on the charging circuit?
I have gone around the board with a MM and cant find anything
Windows shows the battery fine,... -
1. Some theory
1.1. Introduction
Almost every laptop has a charging circuit of some sort, that does a few things:- Manages switching between AC adapter and battery power
- Manages battery charging and generates power rail to charge battery
There are 2 different designs to handle switching between AC adapter and battery power and feeding the system:- Hybrid power boost (HPB) and traditional circuits without power boost (see Warning in HPB section)
- Narrow VDC (NVDC)
Texas instrument has a nice overview of these technologies with some more details at https:... -
since i couldn't find schematic or boardview for this model (LA-K062P), i use closest board model found here https://www.badcaps.net/forum/troubl...-and-boardview
the schematic share same marking for each component, using same PD-Controller, same BQ25710, the only different is the battery cell used. LA-K061P uses 3S battery while LA-K062P use 4S battery per schematic.
what i've done:
- flashing... -
This specification for the Samsung NP750XDA-KDBUK Notebook can be useful for upgrading or repairing a laptop that is not working. As a community we are working through our specifications to add valuable data like the NP750XDA-KDBUK boardview and NP750XDA-KDBUK schematic. Our users have donated over 1 million documents which are being added to the site. This page will be updated soon with additional information. Alternatively you can request additional help from our users directly on the relevant badcaps forum. Please note that we offer no warranties that any specification, datasheet, or download...09-07-2024, 03:10 AM
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