# IBM Thinkpad T20 CMOS Battery



## stuff4 (Jun 30, 2008)

Hi,

Each time my Thinkpad T20 starts it points me to the BIOS where I simply set the Time and Date (which shows incorrectly 00:00 etc.), I Save and Exit then all is fine.

Does the CMOS Battery need replacing?

If so, where can I find details of what battery is required and a description of the process for changing it.

Thanks 

PS I have found (via links on this site) a PDF Manual for the T20.
When they mention the "Backup Battery" are they referring to the CMOS battery?

ftp://ftp.software.ibm.com/pc/pccbbs/mobiles_pdf/62p9631.pdf


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## TriggerFinger (Jan 30, 2008)

yup i think that is the one too.


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## stuff4 (Jun 30, 2008)

Thanks Trigger


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## badgersbum (Jun 25, 2008)

Replacing the CMOS battery is cheap and a doddle, search ebay for CMOS battery for T20, last one I bought was £3; the little devil is under the main battery, undo 1 screw, swap battery, 10 minutes tops!
Have fun!


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## stuff4 (Jun 30, 2008)

Thanks Badger!


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## crave420fubar (Sep 17, 2008)

1. The battery backup is (if you look at the back of the yellow shrink wrap) a CR2032. This is a common battery that can be found in most stores (in fact most desktop/tower computers) that sell watch batteries. So cut the shrink wrap open remove the wires from the DOA battery and replace wires in good battery with a piece of tape to insulate the connectors and hold them in place. Hence saving about $3-4 (they usually sell for about $1.50 in the US) and shipping

2. *IF YOU NEED TO RESET THE SVP PASSWORD READ THIS FIRST!!!*

If you read the manual for the T20 it says that you can reset the POP (AKA SVP) password (P. 26-27) 

"Passwords
As many as three passwords may be needed for any
ThinkPad computer: the power-on password (POP), the
hard-disk password (HDP), and the supervisor password
(SVP).
If any of these passwords has been set, a prompt for it
appears on the screen whenever the computer is turned
on. The computer does not start until the password is
entered.
Exception: If only an SVP is installed, the password
prompt does not appear when the operating
system is booted.
Power-on password:
A power-on password (POP) protects the system from
being powered on by an unauthorized person. The
password must be entered before an operating system can
be booted.
Hard-disk password:
There are two hard-disk passwords (HDPs):
v User HDP—for the user
v Master HDP—for the system administrator, who can use
it to get access to the hard disk even if the user has
changed the user HDP
Note: There are two modes for the HDP: User only and
Master + User. The Master + User mode requires
two HDPs; the system administrator enters both in
the same operation. The system administrator then
provides the user HDP to the system user.
Related service information
26 ThinkPad T20, T21, T22, T23 (MT 2647/2648)
Attention: If the user HDP has been forgotten, check
whether a master HDP has been set. If it has, it can be
used for access to the hard-disk drive. If no master HDP is
available, IBM does not provide any services to reset
either the user or the master HDP, or to recover data from
the hard-disk drive. The hard-disk drive can be replaced
for a scheduled fee.
Supervisor password:
A supervisor password (SVP) protects the system
information stored in the IBM BIOS Setup Utility. The SVP
must be entered in order to get access to the IBM BIOS
Setup Utility and make changes to system configuration
settings.
Attention: If the SVP has been forgotten and cannot be
made available to the servicer, there is no service
procedure to reset the password. The system board must
be replaced for a scheduled fee.
How to remove the power-on password
To remove a POP that you have forgotten, do the
following:
(A) If no SVP has been set:
1. Turn off the computer.
2. Remove the battery pack.
For how to remove the battery pack, see “1010 Battery
pack” on page 60.
3. Remove the backup battery.
For how to remove the backup battery, see “1020
Backup battery” on page 61.
4. Turn on the computer and wait until the POST ends.
After the POST ends, the password prompt does not
appear. The POP has been removed.
5. Reinstall the backup battery and the battery pack.
(B) If an SVP has been set and is known by the servicer:
1. Turn on the computer by pressing and holding F1.
2. Enter the SVP. The IBM BIOS Setup Utility menu
appears.
3. Select Password, using the cursor keys to move down
the menu.
4. Select Power-On Password.
5. At the Enter Current Password field, enter the SVP.
6. When the Enter New Password field opens, leave it
blank and press Enter twice.
7. In the Changes have been saved window, press Enter.
Related service information
General descriptions 27
8. Press F10; then, in the Setup confirmation window,
select Yes .
How to remove the hard-disk password
Attention: If User only mode is selected and the user
HDP has been forgotten and cannot be made available to
the servicer, IBM does not provide any services to reset
the user HDPs or to recover data from the hard-disk drive.
The hard-disk drive can be replaced for a scheduled fee.
To remove a user HDP that has been forgotten, when the
SVP and the master HDP are known, do the following:
1. Power on the computer by pressing and holding F1.
2. Enter the SVP. The IBM BIOS Setup Utility menu
appears.
3. Select Password, using the cursor keys to move down
the menu.
4. Select Hard-disk x password, where x is the letter of
the hard-disk drive. A pop-up window opens.
5. Select Master HDP.
6. Enter the master HDP; then leave the New Password
field blank and press Enter twice.
7. Press F10.
8. Select Yes in the Setup Configuration window.
Both user HDP and master HDP will have been
removed."

But please read carefully as it says "if no SVP has been set". Also if you actually read/look through the table of contents you will see a Security Chip being mentioned. This is where your SVP password is stored. I have not tried as of yet (busy) but it may be possible to remove this chip and bypass the SVP. THIS WOULD MEAN NO SVP EVER!!! Or it maybe possible to replace this chip with another that has no SVP stored or has a known SVP. Because of how this chip is made it does not need power to maintain it's memory like a BIOS chip.


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## ibmer (Jan 19, 2011)

Here are instructions how to remove bios battery on IBM T20 

Here are instructions how to disassemble T20 laptop


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