i have this lenovo thinkpad and i want to connect the charger directly to motherboard.i connected it only the + positive and - negative but it says unknown charger and then shutdown
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Re: Lenovo E555
Hi, those finicky Lenovo, have you connected the third wire for the adapter identification (ADP_ID)? -
Re: Lenovo E555
No the adapter has only 2 wiresComment
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Re: Lenovo E555
Maybe that's the problem, you need an adapter with the ID wire of the adapter.Comment
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Re: Lenovo E555
No the adapter is the original one.i have just cut the end to show the wireComment
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Re: Lenovo E555
These notebooks have an ID pin, but it doesn't go to a serial chip in the AC adapter like some do (e.g. Dell). Instead, there is a resistor between the ID pin and ground inside the plug. The value of the resistor indicates the wattage of the AC adapter. There is no ID wire needed between the plug and the body of the AC Adapter, and so if you cut open the cable, there will only be 2 wires.
Check out this page for likely resistance value required.
Looks like you probably need at least a 280 ohm resistor between the ID pin and ground to indicate an AC adapter of at least 65W.Comment
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Re: Lenovo E555
I knew that on the motherboard you have some kind of adapter ID, I did not know it was a resistance in the plug, I'm learning something new every day.Comment
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Re: Lenovo E555
I also put the resistance because i found it at thr entry of the charger and still the sameComment
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Re: Lenovo E555
If the resistor is the same value as the one in the plug, and the AC adapter supplies the right voltage, and everything is connected to the correct pins, then the problem must be elsewhere.
I don't have a schematic for that board. But if it is like the other ones, it uses the resistor in the plug as the bottom resistor in a resistor divider between 3V and ground. Measure the voltage on the ID pin and make sure it is not 0V or 3V. it should be somewhere in between.Comment
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Re: Lenovo E555
Here how the problem is.the charger port was damaged and also the charger tip.so i cut both of them and want to connect directly.there is no problem with the board.i have done many like this but no one like this lenovoComment
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Re: Lenovo E555
Also the charger has only 2 wire not threeComment
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Re: Lenovo E555
I already explained why the cord has only 2 wires. There is a resistor inside the charger plug (the one you cut off).
The DC jack has 5 pins. 2 are power, 2 are ground, and the middle one is the ID pin. You must attach a resistor between the ID pin and ground. It must be the correct value (280 ohms for a 65W charger, or 550 ohms for a 90W charger).
With the resistor in place, the voltage on the ID pin must be above 0V and below 3V (probably 0.65V with a 280 ohm resistor, or 1.27V with a 550 ohm resistor).
We must know what resistor you used and what voltage you measure on the ID pin. There is nothing else that can be done until you confirm those things.Comment
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Re: Lenovo E555
The charger is 40W.i put an 100 ohm resistor and it burnedComment
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Re: Lenovo E555
Hmm 40W is an odd value. I can find 45W and 65W chargers for some E555s, but not 40W. Though there are some 40W chargers for the Yoga series. In any case, there's no way the resistor will burn if connected between the ID pin and ground (unless something is quite wrong with the board). However, it will definitely burn if it somehow gets connected between 19V/20V and ground.
The 5 pins on the DC jack are:
(1) Ground
(2) Power (19V-20V)
(3) ID
(4) Power (19V-20V)
(5) Ground
The resistor goes between pin 3 and ground. Ground can be pin 1 or pin 5 or any other nearby ground point. Before attaching the resistor, there should be 3V on the ID pin. After attaching the resistor, there should be somewhere around 0.4VComment
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Re: Lenovo E555
i put an 200ohm resistor and voltage to pin 3 is 16vComment
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Re: Lenovo E555
That's not correct. What are the voltages on the 5 DC jack pins without the resistor connected?Comment
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Laptop Question
Hello,
I'm working on a Lenovo T460 that has been having trouble charging as of late. Its worked well since I've owned it for a few years. When I went to use it the other day it was dead and wouldn't turn on (was sitting on an Anker 65W GaN charger). After some fiddling with the charger I got it to turn on and start charging, but seemed like the charger was not working as it should (took a few plug and unplug cycles to get it to start charging).
A day later it was dead again and wouldn't boot/charge no matter what I did. No lights or anything when... -
Hi everyone.
First, let me preface by saying that I do not have much experience with diagnosing damages in motherboards other than visual inspection and checking simple short to ground faults.
But I do learn quickly, and really want to learn how to properly diagnose motherboard faults. If someone could have the patience to go over this board with me, it would be greatly appreciated.
A customer came into my shop with a A2179 MacBook with an 820-01958-A logic board. The reason for bringing the laptop in is that the laptop stopped turning on.
First thing...02-15-2024, 05:30 PM -
Hi everyone,
I'm having an issue with my Lenovo ThinkPad P43s. The laptop does not power on when the internal battery is connected, but it works fine on AC power alone (battery disconnected). Once the battery is reconnected, the system becomes completely unresponsive — no lights, no fan spin, nothing.
Here's what I've tried so far:- Power/EC reset (held power button for 60 seconds with battery and AC disconnected)
- Booted successfully on AC power only with the battery disconnected
- Visual inspection of the battery — no swelling, burn marks, or connector damage
- Battery
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Hi guys, well the summary is this:
the equipment arrived because it did not turn on (it had been the original 230w source the problem) then I feed with my regulated source and without wanting to invert the poles. the equipment turned on and turned off.
This damaged the charger and its mosfets both high and low switching.
It also damaged the input mosfet (pq102).
by chance i had another lenovo legion just like this one and i removed the components and tried to turn it on and it turned on but ....... it burned again the high and low mosfets and switch (pq104, pq105, pq103)....05-23-2024, 10:03 AM -
I have Latitude 5420 that it's working fine on battery but when it's plugged on USB C charger it wont turn on.
Battery is charging fine. Also, if I connect the charger while laptop is on, everything is fine, it will charge.
The same thing if I connect to other USB C port.
Charger is OEM
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