liquidzorch
Senior Member
Last Activity: 11-21-2024, 12:02 PM
Joined: 10-18-2016
Location: coahuila
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Lenovo 15iml05 Power led lights for 12 seconds then off 12 seconds
Hello. I bought a faulty Lenovo ideapad 3, but it turns out the 3Valw buck converter burnt a hole through the board. I was able to clean it up, and remove all the shorts. I now can power the 3.3v rails from a bench power suppy while connecting the laptop to its psu, and I get the additional 5valw, 1.8v, and 1.05v, form what I can tell in the schematics, those are the only 4 voltages I should see before turning on, and they are present. When I hit the power button, the power indicator on the left side turns on (not the one on the power button), stays on for about 12 seconds, then turns off for... -
Thank you for all your help. I have found the charging problem. Phase was not connected form the mosfet to the BQ, it runs below Q3 mosfet, so I guess when the mosfet burned, it damaged the phase line. I made a temporary jumper and it is now charging and swapping between battery and AC. The only thing left is to adjust the ILIM voltage divider, I am guessing that I should leave it at 1.6v, to disable the voltage divider option and make it check it's programming (if I understand the datasheet correctly). Right now I have ir at 1v, which I have not done the calculations as to see what charging amperage... -
esistance between SRN and SRP pins is about 15ohms. I can confirm ACOK is stable at 3.3v in all conditions when ac plug is connected, as I already checked that, thinking the same. ACDET pin is 2.01v (which is below what data sheet says it should be but this is a BQ728H and the datasheet I am looking at is for a BQ24725, maybe a bit different? as with this 2.01v it does turn on.
And an update. I replaced the q3 mosfet again, and got it to charge for a quick 2 seconds, when plugged ac in, the orange led flashed twice, then stable, and when it went stable, the charging stopped. And now,...Leave a comment:
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It does seem to be something to do with the missing ILIM resistor. Reading the datasheet, it says to calculate a 1.6v voltage on ILIM to disable external regulation and stick with the programmed limit. That's what I did. I also tried 1v on ILIM, but still the same thing. If I remove the resistor from 3.3v to ILIM, I now get AC power on ssytem rail, instead of battery, but no charging. So, without a voltage on ILIM I can use the battery, use the ac, hot plug and hotunplug the battery and it swaps between the two, just no charging (even though the led is orange whe both are connected)....Leave a comment:
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Battery mosfet:
S-D: 3.6Mohm
S-G:2.5Mohm
G-D: OL, reversed leads: above 1 Mohm
The two dc mosfets are also all in the megaohm rangeLeave a comment:
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Ok. So I finally found the fault, and now ac in works, but I have a problem. If the battery is connected it works, but the light goes orange and does not charge the battery. The batfet mosfet will choose for the system to use battery instead of ac. If the battery is disconnected, the acfet turns on and the system will use ac power. If I disconnect the battery while ac is in, the thing will just turn off, and never seitch from battery to AC. So it's either one or the other. While the image below is from the datasheet, not the laptop. It seems the laptop is pretty close to the same. The fault it...
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Thanks, the resistor that is still attached is going to gnd, it's a 10k if I'm not mistaken as I was checking it yesterday. If it's a voltage divider circuit to determine the max amperage, then I could calculate it, but I don't know the max current this laptop should deliver to the battery. I will check on the sticky you mention. Thanks agian.Leave a comment:
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Missing resistor on BQ ILIM pin. DA0P5JMB6D0
Hello. I can't find the schematics anywhere for this motherboard, does anyone have one, and can give me the resistor value for the BQ728H missing in pic below? I already read the dadsheet, and this resistor value is calculated, so I can't just go with whats in the "typical" diagram.
On a second note, could this resistor cause it to only boot with the battery and not the charger? It boots fine with a charged battery, but will not turn on with the charger (nor charge). The 19v does not get past the first mosfet, it recieves pulses to turn on, but something is preventing it.... -
Re: Xbox Series X shuts off after ~6 seconds
Those are 0 ohms. Try looking at u82, that seems to blow if anything is shorted at the HDMI connector. There should be 3.3v on pin 1 I believe. And when turned on, pin 6 should have 3.3v. If pin 6 doesn't get 3.3v when turned on, replace the u82, you can find them on other boards. Any chance you could take a measurement of the GPU core voltage side to ground, how much resistance do you get?...Leave a comment:
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Re: Xbox Series X mosfet controller questions
Here is a snip of the schematic, it's the MEMIO controller. This controller has a datasheet, unlike the gfx controller. And if I understand it correctly, once EN goes high, there should be a PWM out each of the PWM lines, but mine only go high.
...Leave a comment:
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Xbox Series X mosfet controller questions
Hello. I got in an xbox series x that was taken apart to clean, then reassembled, after that, it powers on then off instantly.
When pressing the on button, I have found that the two ic's that control voltage to the memio, memphy (MP2926) and cpu, gpu (MP2855) DO recieve an EN signal, and probing the pwm outputs (that go to the intellegent mosfets (MP86965)) of both of the ic's go high, but there is no PWMing (probed with oscilloscope).
So the EN pin goes high, the PWM output (all of them) goes high for about half a second, then everything goes low again.
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Re: Acer Nitro 5 randomly doesn't power on (but charge light is on)
Thanks, I'll see if I can clean it. It would be so much easier if it would always be failing, that way I know if what I have done to it has fixed it.Leave a comment:
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Re: Acer Nitro 5 randomly doesn't power on (but charge light is on)
I waited until the laptop wouldn't power on, the day it wouldn't, I flipped it over and probed the power button (pin 1 keyboard connector), and while pressing the power button it would go down, but only to 1.4v. So I shorted pin 1 to gnd and it powered on. So it is the power button.
After doing that, it has once again started to work normally (the power button does lower the button rail to 0v when pressed). So my new question, why? Checking resistance to gnd when pressed, I get 140ohms on pin 1 (when...Leave a comment:
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Re: Acer Nitro 5 randomly doesn't power on (but charge light is on)
The bad thing is, my friend (the owner of the laptop) says it can go for days or even weeks without failing, but all of a sudden it will just stop powering on. The charge light will come on if connected, but no power when power button is pressed.
When he brought it to me, it was in this state, I couldn't turn it on, I even tried pressing the power button hard, and for over 30 seconds, nothing happened. I opened it up unplugged the battery and re plugged it, and it worked for one boot up. Then I shut...Leave a comment:
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Re: Acer Nitro 5 randomly doesn't power on (but charge light is on)
Yes, the power switch is in the keyboard. I have visually inspected the board quickly with a magnifying glass, I see no noticable damage.Leave a comment:
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Re: Acer Nitro 5 randomly doesn't power on (but charge light is on)
When it fails, it will not power up on only battery nor with charger connected. I did get to test some coils when it was failing, and the only voltage that was present when off was 5v, which according to the schematic, is correct, 5vALW is the only voltage that is present when off and charger connected (besides the battery and charger voltage of course).
RTC power should always be present, but I have not been able to check it since now the laptop has not failed to power on again... I am waiting for...Leave a comment:
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Acer Nitro 5 randomly doesn't power on (but charge light is on)
Hello. I have an Acer Nitro 5 AN515-44-R58M here that randomly will not power on. It can be good for some days, then all of a sudden it will not power on, the battery charge light will be on, but no signs of power. To get it to power on, sometimes what will work is disconnecting and reconnecting the battery, but it doesn't always work.
It is hard to diagnose since I can't reproduce the issue (get it to not turn on). Right now it powers on, so I probably won't find any missing voltages, but it's been doing this for months, where you press the power button and nothing happens, even... -
Re: Lenovo L340-15API BIOS Dump needed
Sorry. I clicked "new post" in the troubleshooting Laptop sub forum, I have no idea how it got here. I never hijack another persons tread. I even had it opened in a brand new tread wating for a response, and responded to my original post, indicating I have solved my issue.
Ps. I am trying to open my thread in the laptop troubleshooting sub forum, and a completly different thread opens (this one). I have been getting issues with badcaps.net opening since yesterday, maybe an issue?Leave a comment:
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Lenovo Bios Recover Serial and Windows license
Hello. I have a Lenovo l340-15API that had a corrupt bios, I backup up its bios, then I flashed a clean bios I found here and it worked, but I would like it recover the Serial number, product IDs and windows license from the old bios (if they are still there). From what I have found, the bios is encrypted, so searching the hex for it's serial wont work.
Is there anything I can do? Can I close the laptop and inject them later? I would really like it if it had all it's proprietary info.
There are two sections...Leave a comment:
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Re: Motherboard swap compatibility HP 15-an and 17T or 15-ab
UPDATE
Just in case anyone has the same question I did. The motherboard did work, but with a few catches.
So first things first, you wil have to swap the battery connector from the old board to the new board, then swap the keyboard connectors from one location to another. AFter that everything will work as intended EXCEPT the monitor. You can use it through HDMI. To get the monitor working, there is a lot of work to be done. If you compare the underside of the board, under the lvds connector,...Leave a comment:
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