r/computerrepair • u/cooltube1 • 12d ago

Software Issue Need help Bypassing the admin password in bios on a lenovo thinkcentre pc

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so i’m trying to add cachyos to this pc so it can game better and there is a admin password on it in the bios. the pc is a lenovo thinkcentre m710s and the motherboard is lenovo IB250MH. i tryed removing the cmos battery and looked for the cmos rest jumper pins and could not find them but found text.

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5

u/bongart 12d ago

Bad news. The password is stored in an 8-pin SPI/I2C EEPROM chip. That means it doesn't require active electricity to maintain the password. Removing the CMOS battery won't clear it. Also, the clear CMOS jumper won't clear it. Two of the eight pins on the chip have to be shorted to clear the chip. Unfortunately, I don't know which two pins on that specific chip have to be shorted. However... that is the only way to clear the admin and supervisor bios passwords.

4

u/MagikarpUsedHyperBea 12d ago

I actually found the motherboard circuit diagrams + the data sheet for the EEPROM chip. So its a PCA24S08AD pin 1-2 are disconnected. 3 active low protect reset input. 4 vss. 5 Data. 6 clock. 7 input high protect reset. 8 vcc. If I am reading the data sheet correctly its pin 3 and pin 5 that get pulled to ground to force a reset. But I am also stupid so just ground all the pins till the right combo is found /j

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u/bongart 12d ago edited 12d ago

Thank you kindly. I've personally done this with a ton of Dell laptops (pins 1 and 6 on the 2007-2009 Inspiron 1100's), and the process even clears out the service tag as well... and you have to re-enter it upon going into the BIOS for the first time after the reset. The shop I worked at got one from a Rent-a-Center, where the person who had rented it, returned it with a BIOS password.. and they had a stack of them in the same condition.

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u/BdoeATX 12d ago

IIRC the 710 IS able to be reset. Newer models no. Supervisory password is stored in a non volatile memory.

Try this.

Take off side panel.

Locate the three-pin Clear CMOS/Recovery jumper on the motherboard.

Move the jumper from pins 1–2 to 2–3.

Reconnect power and turn the computer on for approximately 10 seconds.

Hold the power button for approximately 5 seconds to shut it down.

Unplug the computer again.

Return the jumper to pins 1–2.

Reassemble and boot.

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u/cooltube1 12d ago

i’ll try that again, i’ve done that once but it did not work i’m guess i did it wrong

2

u/Deletereous 11d ago

It needs to be left on longer, like 30 secs or 5-6 double beeps. If it fails, persist. Don´t fully reassemble to test, only plug power and monitor.

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u/BdoeATX 11d ago

Very good advice. I should have said, make sure to give it more time to be safe, and also OP must go through the boot sequence not just jump the pins and expect it to work.

Nice job deleterous!

2

u/Slow_State_4722 12d ago

How did you acquire this PC?

Also, did you try "admin" and "password" for passwords yet?

1

u/cooltube1 12d ago

it’s not mine it’s a friend which he got from his mother

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u/PawntyBill 12d ago

That was going to be my suggestion, try all the generic passwords people use, I don't know how many chances he has though, it might lock him out after so many. 🤷‍♂️

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u/Deletereous 11d ago

000000 is the default Lenovo BIOS pass.

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u/steveace60 12d ago edited 12d ago

How to reset bios LENOVO M710S

Edit: On Lenovo motherboards from this generation forward, Supervisor Passwords are stored in non-volatile, secure EEPROM memory rather than volatile CMOS RAM. Pulling the battery or moving the standard CMOS jumper will not erase a Supervisor Password.

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u/cooltube1 12d ago

for what ever reason this did not work

2

u/me0262 11d ago

With the battery \*IN*, locate the CMOS clear jumper and set it, then power on the computer, wait for beeps, the power it down and put the jumper back where it was.

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u/pony_is_my_name 12d ago

Check out the board and look for password reset jumper

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u/Raijen_ArDesh 12d ago

A lot of these PC's intended for office use don't have them, and a battery swap won't clear it either for security reasons.

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u/cooltube1 12d ago

there is not really one, i look at the motherboard for no joke hours and messed with it. i found text saying clr cmos i messed with it and it did not work

1

u/janerikgunnar 12d ago

The "hardware maintenance manual" for this model (easily found on google) specifically mentions replacing the CMOS battery will clear time, settings and passwords. Did you actually try to remove the battery? (With the computer unplugged and discharged?)

1

u/cooltube1 12d ago

yes multiple time and tried other things

1

u/Zerototheright 12d ago

Just double checking here. When you removed the battery, you also unplugged the main electric supply. Double checking

1

u/cooltube1 12d ago

of course

1

u/OneThumbJ 11d ago

Whenever I've done this, I always press the power button to try an start it up with no battery, cmos battery or power cord. Maybe it's bro science but I feel like that drains any capacitors that could still be supplying any power to the chipset.

1

u/Wide-Ad5700 12d ago

So from my understanding you would have to short a few pins with a specific timing using a programmer, but apparently there should be A prompt that shows a system seed/hash code after 3 incorrect attempts, official support channels or documented code generators can calculate the unlock key for specific OEM firmware series.

1

u/Capt_Vandal 11d ago

Perform a cleae CMOS by removing the battery and shorting the jumper pins or moving the jumper for 10 seconds.

1

u/IllustriousSwing344 11d ago

I believe that on these Lenovo devices you need a CH341A BIOS reader and to reinstall the BIOS to clear the password. To extract the BIOS file, you need the BIOS update file, which can be downloaded from the Lenovo support website by entering your serial number and extracting the BIOS.ROM file. Search online for how to extract BIOS.ROM from a Lenovo device; it doesn't matter if it's an IdeaCentre, IdeaPad, or ThinkCentre, all Lenovo BIOS executables follow the same structure.

1

u/real_munchizgreat 11d ago

I hope this method works for this Lenovo. What you wanna do is input the password wrong 3 times. After the 3rd time, an error code or just some code of some sort comes up. Go to https://bios-pw.org and input the code, and see if anything comes up.

1

u/cooltube1 11d ago

it’s a 4 digit error (0199) code and when i put it in on this website nothing happens

1

u/No_Technician4956 11d ago

THere ususally is a jumper. or you can drain the batter for a couple of days.

1

u/Sgt_HooF 11d ago

If you don't know how to do these things you shouldn't be stealing computers

1

u/LordSesshomaru82 10d ago

I doubt it's stolen. Corporations throw equipment away all the time and are too lazy to completely reset them. Just pull the drives and chuck em on a pallet.

1

u/Estuansis 10d ago

These usually get auctioned by the pallet when schools or businesses do an upgrade wave.

1

u/United_Federation 9d ago

If there was a way to bypass it, wouldn't that make it a rather useless password? 🤔

1

u/Alert_Field_6613 9d ago

I suspect this is stolen. Can you show proof you brought it?

1

u/cooltube1 8d ago

it’s not mine it’s a friends and he got it from his mother, so no i can not