And well, I got trolled!
Basically it was a faulty charger, I tried with a charger that i had lying around and it started.
What an embarassment, well, I hope next time it's a really good fault...
I got a message from the bios saying it's faulty, will check that tomorrow.
Cuboy
Member
Last Activity: 08-17-2024, 03:02 AM
Joined: 12-30-2018
Location: Tarragona
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When shorting the mosfet Q1025 gate and drain, i get around 6v for LS_100R which makes the charging light go on for a second which makes me suspect even more from the adapter.Leave a comment:
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Okay [USER="295753"]mon2[/USER] so I have ended with a hipotesis on what could be happening. Tell me what do you think.
Basically, i see that LS_100R should be higher than the VADP voltage in order for the first mosfet to allow voltage to the second mosfet.
This lead me into Q1025 mosfet, while testing it, I see that the gate has 6V, which tells me that Q1025 must be closed (conducting, for a better word). I see that Q1025 source has 0V. drain has around 1v but we're not interested on that.
This leads me to LIMIT_SIGNAL, which is the voltage...Leave a comment:
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Yes, 0V from the battery, i have tried both ways (since i dont have a + and - sign on the battery)
Thanks for your help, i really appreciate it....Leave a comment:
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I cannot measure any voltages in the battery, it's 0v but i am not too sure since it's also haven't been used for a long time...Leave a comment:
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I don't have any tool to measure battery voltage, the battery is hstnn-ib89, is it possible to use the multimeter?
I am looking at some videos to see how....Leave a comment:
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Well that's exactly my question, it's strange, but after having the meter connected to ground for a while it dropped to 0V (maybe some coil/capacitor charge?)
resistance is OL
I think the multimeter on voltage mode discharges something and on resistance mode charges that...Leave a comment:
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No, I have removed the battery, i have dissasembled the laptop and have the motherboard out
voltage on +VBATR is 1V but is going down...Leave a comment:
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I have posted the wrong diagram, i have updated it on the second answer (but yes, q25 is q1032 in this diagram, it's the same but references change, the second one has the same references than my board)
U1-B/ U1006-A :
PIN 5: 0V
PIN 6: 0V
PIN 7 / ADP_PRES: 0.0046V
PIN 8: 0V
For the voltages on q25 (in my board it's q1032, which is the first dcin mosfet)
GATE: 19V
SOURCE: 19V
DRAIN:0V
The Q1018 which on my board and second schematic is Q1033
GATE: 18V
SOURCE: 19V
DRAIN: 19V
...Leave a comment:
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diagram with the correct references...
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Hello thanks for the answer
You're right, the comparator U8 seems to be part of a control circuit that enables or disables the P-channel MOSFET Q1032 based on the input voltage from the power adapter.
Looking at the schematic, there is indeed a voltage divider formed by resistors R130 and R136 connected to the non-inverting input (pin 5) of the comparator.
This is the schematic: [URL]https://www.badcaps.net/forum/troubleshooting-hardware-devices-and-electronics-theory/troubleshooting-laptops-tablets-and-mobile-devices/schematic-requests-only/3236536-hp-probook-4510s-schematic[/URL]...Leave a comment:
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HP probook 4510s mosfet issue
Hello,
I am currently trying to help a ONG by volunteering to help repair laptops, it's something that i have been into since 2017, always watching videos, on discords, forums etc...
I have an HP ProBook 4510s laptop that does not power on and has no indicator lights, which suggests an issue with the power supply or the motherboard.
I started by verifying that there is voltage at the input of the motherboard, confirming that the power adapter is working correctly. However, when I checked the voltage at the output of the first MOSFET (Q1032), I found 19V at... -
Someone on discord help me read the contents of the bios after i tried to boot it, it seems that it doesn't get to the Management Engine inside the PCH.Leave a comment:
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Flashed the bios with a good known bios, same result.Leave a comment:
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Here are the voltages remeasured again, from the lower load side....
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Here is voltage, i have followed the [USER="169897"]piernov[/USER] guide on diagnosing the laptop power supply, but seems that the power supply works correctly since i always get the 19v from the current sensing resistance.
The measurements of the voltage are taken when the led indicates that it's going to power on (the white led goes on, and after a bit off), there's an orange led that indicates that the charger is plugged in but when measuring voltage in that state, almost everything is around 0V but the dc in circuitery.
When plugging the charger, the orange...Leave a comment:
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Hello I have already measured resistances to ground, going to measure voltages. So far, it seems that the current sensing resistance has 19V on it (this explains why the laptop tries to boot).
I think the top has no current sensing resistors and coils, correct me if i am wrong....Leave a comment:
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Oh okay, I didn't know that vcore had such a low resistance.
Okay, will try....Leave a comment:
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Asus X540UV vccore short
Hello everyone,
I have got a Asus X540UV rev 2.0, this was sold to me a couple years ago and it came not working. I left it on the shelve until today.
When i plug the charger and light it on, the laptop tries to power, I see a couple of leds and then goes off. The screen doesn't power on, the hard disk spins.
I have been trying to diagnose it, and I have noticed that the vcore rail is shorted to ground, all capacitors from the rail have a low resistance to ground, I've got a 10 ohm resistance from the vcore side to ground, These are PC8125, PC8134... from...
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