[B]UPDATE[/B]
I was finally able to test the battery and its working as anticipated! At least that's good news.
The system powers up no problem with the battery.
However something strange is now happening. The charger when plugged in takes time to respond and show up on the system as charging and once it does its now making a hissing sound (The AC Adapter itself). Other than the hissing sound nothing seems particularly amiss. The battery is charging and working as normal just that the hissing sound is honestly unnerving for me.
It makes the sound...
Neddsme
Member
Last Activity: 02-10-2025, 08:31 AM
Joined: 09-14-2021
Location: Lilongwe
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Well to quickly summarize the process i followed these steps;
1: I opened the battery and had direct access to the cells. then i measured each cell pair coz it was a 2S2P battery pack and found that they were all discharged beyond 3V but one of the cells was lower than the rest (2.56V vs 2.70V). This imbalance was enough to ensure the battery would lock up.
2: I then charged up the cells with a custom balance charger ensuring that the cells were equalized and that afterwards the shady cell did not discharge beyond its 2 counterparts indicating a potential capacity degradation....Leave a comment:
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[B]UPDATE:[/B]
first of all apologies because i have been busy this last week i did not have time to work on this at all.
I was able to confirm that the battery was in permanent failure and it seemed to shut down the charging circuit possibly as a safety precaution am guessing.
Some of the voltage levels as pointed out do seem a bit off still, but without a working battery I was limited since the laptop works fine now on AC
but the battery charging was the only issue that was still uncertain.
I tried finding a replacement but all my local shops...Leave a comment:
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In diode mode there is .463 voltage drop
in resistance it reads 12.4K...Leave a comment:
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Yes that's true. The DC-in mosfet source and drain was shorted. I didnt pick that up initially because it did not short to ground. I replaced it along with fixing the CMSRC track.
This circuit is becoming a bunch of spaghetti now. a schematic would have made things a bit simpler lol.
The battery pack is perfectly balanced at 3.69v but does not output voltage
from the report it shows 10% charge. could it be locked?...Leave a comment:
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Yes the 2.3v is coming from a rail with 3.38v. the resistor in between is 15K (resistance measured while power is disconnected)....Leave a comment:
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Unfortunately i don't have the schematic. that would have saved me a lot of guess work. I did a search on the forums and someone already posted a request for this specific model's schematic and boardview but nothing turned up so i didn't want to create a redundant thread. I am keeping tabs on that thread incase someone finds it.
As for the resistors, i am just as puzzled as u are why the implementation has 100 ohm resistors on it. the battery current sense path does not have these resistors only the AC side. A guess would be maybe coz its a heavy power system? it uses like a 150Watt...Leave a comment:
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[B]NEW DEVELOPMENTS[/B]
Yes! as it turns out there was a broken track on CMSRC, probably it suffered some physical damage during disassembly.
After finding the anomaly and fixing it, there are some new readings now.
ACN ~ 19.7v
ACP ~ 19.7v
CMSRC ~ 19.7v
ACDRV ~ 25.4v
ACOK ~ 2.3v
ACDET ~ 2.7v
BATSRC ~ 12.0v
BATDRV ~11.99v
SRN ~ 11.98v
SRP ~ 11.99v
ILIM ~ 3.37v
LODRV ~ 0v
REGN ~ 6.0v
BTST ~ 5.74v
HIDRV~ 12.33v
PHASE ~ 12.01v
VCC ~ 19.16v
I don't know the specifics...Leave a comment:
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For the ACN/ACP measurements it was from the pins of the IC to the CLR.
Just to make sure I retook the measurements;
ACN/ACP to GND = OL
CLR ~ 2 ohms
ACN to ACP on the IC ~ 200.6 ohms
ACN/ACP to CLR ~ 100.5 ohms
The resistor in between CLR and IC ~ 100.4 ohms
There is no short to ground, just an "odd addition" of 100 ohm resistors to the ACN/ ACP path....Leave a comment:
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Unless I am doing it wrong, but the ACN and ACP pins on the IC have some resistors in series with the tracks on the path to the current sensing resistor. the current sense resistor measures 0.5 ohms on its own but measuring from the pins of the IC to the current sense points I get 100.5 ohms. And yes this is with power removed. the only measurements taken with power were voltage readings.
I am assuming there are 100 ohm resistors added to the path maybe? IDK...Leave a comment:
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Yes, i removed the bypass after verifying it turned on then started taking all these various measurements....Leave a comment:
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Thanks for the swift reply!
1, the bypass of the DC-in was really just a hypothesis test on whether the laptop was dead and not a solution. I know very well the importance of the seemingly "unimpressive" DC-in FETs
2, Yes the FETs are known good N-type equivalents. and the drain of the FETs makes it next to impossible to solder it the wrong way, the drain is most of the pad.
3. the CMSRC voltage is at 0.22v
4, the ACP/ACN is both 100.5 ohms
5, the SRN/SRP is 0.1 ohms and 0.2 ohms...Leave a comment:
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Hp ZBook 17 g3 battery not charging issue
I have the laptop mentioned in the title and i am in a bit of a pickle. The laptop Power circuit got fried after someone messed with the charger and the DC input MOSFETS were toasted. I replaced them but now it turns on and works on charger only after bypassing the FETS, they dont turn even though the charger LED is ON. The bettery on the other hand no longer charges at all.
After a series of multimeter testing I concluded there is no more short but the BQ24780 chip is looking suspicious to me. Here are some voltage readings i think are relevant;
ACN ~ 19.7v
ACP ~ 19.7v... -
Re: Need bios hp la-e841p
oooh alright. so i got that part down, it says **BID08330**.
now the second part on "DMI" is that also about the bid or something else?...Leave a comment:
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Re: Need bios hp la-e841p
I am sorry i dont quite understand what you mean?...Leave a comment:
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Re: Need bios hp la-e841p
alright sorry i have been preoccupied. i had some trouble getting the serial but here is the info that may be relevant.
Bios ver. F.31
Product Number: 4US67EA#ACQ
Serial Number: CND8486FF7...Leave a comment:
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Re: SANSUI SLEDSC-32HD TV not booting, No stand-by led
update on the board, Turns out the board is identified as TP.MS338.PB802
An android TV board with 4GB storage....Leave a comment:
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SANSUI SLEDSC-32HD TV not booting, No stand-by led
I have a 32 inch Sansui android TV that stopped booting. i checked the motherboard for any power failures but it seemed OK to the best of my knowledge. The TV does not have a dedicated power supply board so i could not do any isolation but here is a list of all the things i think were relevant to test.
if i missed anything you let me know;
DDR (1.5V) = 1.484V
VDDC = 1.000V
VDDC_CPU = 1.151V
VDD1V2_DM = 0.000V
3V3_STB = 3.315V
3V3_M = 3.307V
1.8V_M = 1.803V
ALL KEYS = 3.310V
5V_STB = 5.142V
5V ... -
Re: Need bios hp la-e841p
Hello dear forum members. I have a problem with my HP laptop and i thought this was the correct threat to post to, i don't know if it is still active.
My board number is LA-E841P Rev 2.0 and it has an AMD E2 APU. google says board family is 15-rb0xx.
Anyway the issue is that the board stopped finishing POST when booting normally. the only way to boot it is to use boot options menu where you have to navigate to .efi files to boot OS otherwise bios doesnt show boot options, doesnt allow editing and doesnt save or reset to default configuration....Leave a comment:
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Re: Thinkbook 15-IIL bios DALVACMB8D0
Hello again.
The bios did not work. I tried 2 files and none work. I assume my original bios might have been okay because I think this is a hardware issue now. After measuring voltages I found abnormal voltage on the DCIN rail. 9.1v instead of 20v. Unless I am missing something there.
Anyway, thanks for the help, but I think I should move my issue to a different thread on hardware troubleshooting.Leave a comment:
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