IBM ThinkPad T20 T21 T22 T23 Service Manual - Revision history

Josh: Update links to IBM ThinkPad Notebooks (A/G/T/X) - Personal Systems Reference after page move

2026-10-01T18:25:18Z

Update links to IBM ThinkPad Notebooks (A/G/T/X) - Personal Systems Reference after page move

← Older revision		Revision as of 19:25, 1 October 2026
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	* [[IBM ThinkPad T30 Hardware Maintenance Manual]], [[IBM ThinkPad A20m/p A21m/p A22m/p Hardware Maintenance Manual]], [[IBM ThinkPad X20 X21 X22 X23 X24 Hardware Maintenance Manual]]		* [[IBM ThinkPad T30 Hardware Maintenance Manual]], [[IBM ThinkPad A20m/p A21m/p A22m/p Hardware Maintenance Manual]], [[IBM ThinkPad X20 X21 X22 X23 X24 Hardware Maintenance Manual]]
	* [[IBM ThinkPad Notebooks - Personal Systems Reference]] (machines withdrawn by January 2001) and [[IBM ThinkPad Notebooks (A/G/R/T/X) - Personal Systems Reference]] (A, G, T and X series withdrawn by May 2005), for model specifications by type-model		* [[IBM ThinkPad Notebooks - Personal Systems Reference]] (machines withdrawn by January 2001) and [[IBM ThinkPad Notebooks (A/G/T/X) - Personal Systems Reference]] (A, G, T and X series withdrawn by May 2005), for model specifications by type-model

	[[Category:IBM Service Manuals]]		[[Category:IBM Service Manuals]]
	[[Category:Service Manuals]]		[[Category:Service Manuals]]

Josh: Merge duplicate page for the same file (UUID and hard-disk password notes from the PDF); drop link to it

2026-10-01T17:52:03Z

Merge duplicate page for the same file (UUID and hard-disk password notes from the PDF); drop link to it

← Older revision		Revision as of 18:52, 1 October 2026
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	The '''IBM Mobile Systems ThinkPad Computer Hardware Maintenance Manual''' of April 2002 is IBM's service manual for the ThinkPad T20, T21, T22 and T23, part number 62P9631, First Edition (April 2002), 182 pages. The title page lists the ThinkPad T20, T21, T22 and T23 (MT 2647/2648) and the ThinkPad Dock (MT 2631). All four models share the two machine types~~. The same file is also on [[IBM Mobile Systems ThinkPad Hardware Maintenance Manual (April 2002)]]~~.		The '''IBM Mobile Systems ThinkPad Computer Hardware Maintenance Manual''' of April 2002 is IBM's service manual for the ThinkPad T20, T21, T22 and T23, part number 62P9631, First Edition (April 2002), 182 pages. The title page lists the ThinkPad T20, T21, T22 and T23 (MT 2647/2648) and the ThinkPad Dock (MT 2631). All four models share the two machine types.

	== Contents ==		== Contents ==
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	* General descriptions (pp. 21-37): read this first, related service information including restoring the preloaded system, passwords (p. 26) and power management (p. 28); checkout guide (p. 32) with PC-Doctor (p. 34) and the power system checkout (p. 35).		* General descriptions (pp. 21-37): read this first, related service information including restoring the preloaded system, passwords (p. 26) and power management (p. 28); checkout guide (p. 32) with PC-Doctor (p. 34) and the power system checkout (p. 35).
	* ThinkPad T20, T21, T22 and T23 series, from p. 39: product overview and specifications (p. 41), status indicators, FRU tests, Fn key combinations; symptom-to-FRU index (p. 49).		* ThinkPad T20, T21, T22 and T23 series, from p. 39: product overview and specifications (p. 41), status indicators, FRU tests, Fn key combinations; symptom-to-FRU index (p. 49).
	* FRU replacement notices (p. 56): screw notices and retaining ~~serial numbers~~.		* FRU replacement notices (p. 56): screw notices, restoring the serial number and retaining the UUID (p. 57).
	* Removing and replacing a FRU (pp. 59-139): numbered procedures from 1010 Battery pack (p. 60) to 3020 ThinkPad Dock top cover (p. 136).		* Removing and replacing a FRU (pp. 59-139): numbered procedures from 1010 Battery pack (p. 60) to 3020 ThinkPad Dock top cover (p. 136).
	* Locations (p. 140) and parts list (p. 143), with the model matrix (p. 146), LCD FRUs (p. 157), keyboards (p. 160) and recovery CDs (p. 161).		* Locations (p. 140) and parts list (p. 143), with the model matrix (p. 146), LCD FRUs (p. 157), keyboards (p. 160) and recovery CDs (p. 161).
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	The power system checkout (pp. 35-37) gives these limits: AC adapter output +15.5 to +17.0 V dc at pin 1; battery pack +0 to +12.6 V dc between terminals 1 and 5, discharged if below +11.0 V dc, and 4 to 30 kΩ between terminals 4 and 5 if above it; backup battery +2.5 to +3.2 V dc on the red wire.		The power system checkout (pp. 35-37) gives these limits: AC adapter output +15.5 to +17.0 V dc at pin 1; battery pack +0 to +12.6 V dc between terminals 1 and 5, discharged if below +11.0 V dc, and 4 to 30 kΩ between terminals 4 and 5 if above it; backup battery +2.5 to +3.2 V dc on the red wire.

	The password section (pp. 26-27) sets out what IBM would and would not reset: a forgotten power-on password can be removed; a forgotten supervisor password has no reset procedure and the system board must be replaced; a forgotten user hard-disk password can be bypassed only with the master hard-disk password.		The password section (pp. 26-27) sets out what IBM would and would not reset: a forgotten power-on password can be removed; a forgotten supervisor password has no reset procedure and the system board must be replaced; a forgotten user hard-disk password can be bypassed only with the master hard-disk password. Without the master password IBM will neither reset the hard-disk passwords nor recover data; the drive is replaced for a fee.

	The screw notices (p. 56) say the screws are nylon-coated, should be used only once, and are tightened by angle (90 degrees past contact for plastic to plastic, 180 degrees for logic card to plastic) or to the torque given in each procedure.		The screw notices (p. 56) say the screws are nylon-coated, should be used only once, and are tightened by angle (90 degrees past contact for plastic to plastic, 180 degrees for logic card to plastic) or to the torque given in each procedure.
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	== Related pages ==		== Related pages ==

	* [[IBM Mobile Systems ThinkPad Hardware Maintenance Manual (April 2002)]], the same file under the cover title
	* [[IBM ThinkPad T30 Hardware Maintenance Manual]], [[IBM ThinkPad A20m/p A21m/p A22m/p Hardware Maintenance Manual]], [[IBM ThinkPad X20 X21 X22 X23 X24 Hardware Maintenance Manual]]		* [[IBM ThinkPad T30 Hardware Maintenance Manual]], [[IBM ThinkPad A20m/p A21m/p A22m/p Hardware Maintenance Manual]], [[IBM ThinkPad X20 X21 X22 X23 X24 Hardware Maintenance Manual]]
	* [[IBM ThinkPad Notebooks - Personal Systems Reference]] (machines withdrawn by January 2001) and [[IBM ThinkPad Notebooks (A/G/R/T/X) - Personal Systems Reference]] (A, G, T and X series withdrawn by May 2005), for model specifications by type-model		* [[IBM ThinkPad Notebooks - Personal Systems Reference]] (machines withdrawn by January 2001) and [[IBM ThinkPad Notebooks (A/G/R/T/X) - Personal Systems Reference]] (A, G, T and X series withdrawn by May 2005), for model specifications by type-model

Josh: Replace invented T20-template contents with the manual's own contents and page numbers; power checkout limits from the manual; capacitor mention corrected; remove unsupported claims; passwords and screw notices from pp. 26-27, 56

2026-09-30T22:03:49Z

Replace invented T20-template contents with the manual's own contents and page numbers; power checkout limits from the manual; capacitor mention corrected; remove unsupported claims; passwords and screw notices from pp. 26-27, 56

← Older revision		Revision as of 23:03, 30 September 2026
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	'''IBM Mobile Systems ~~—~~ ThinkPad Computer Hardware Maintenance Manual'''~~, '''~~April 2002''', part number ~~'''~~62P9631~~'''~~, ~~'''~~First Edition~~'''.~~ 182 pages.		The '''IBM Mobile Systems ThinkPad Computer Hardware Maintenance Manual''' of April 2002 is IBM's service manual for the ThinkPad T20, T21, T22 and T23, part number 62P9631, First Edition (April 2002), 182 pages. The title page lists the ThinkPad T20, T21, T22 and T23 (MT 2647/2648) and the ThinkPad Dock (MT 2631). All four models share the two machine types. The same file is also on [[IBM Mobile Systems ThinkPad Hardware Maintenance Manual (April 2002)]].

	~~It supports '''ThinkPad T20, T21, T22 and T23 (MT 2647/2648)''' and the '''ThinkPad Dock (MT 2631)'''.~~		== Contents ==

	~~== What it contains ==~~		Page numbers are the manual's own.

	~~IBM's~~ ThinkPad ~~hardware maintenance manuals all follow~~ the ~~same plan~~, and ~~knowing it saves hunting:~~		* Introduction (pp. 1-18): strategy for replacing FRUs and how to use error messages, diskette compatibility matrix, safety notices in English, French, German, Italian and Spanish, safety information and the laser compliance statement.
			* General descriptions (pp. 21-37): read this first, related service information including restoring the preloaded system, passwords (p. 26) and power management (p. 28); checkout guide (p. 32) with PC-Doctor (p. 34) and the power system checkout (p. 35).
			* ThinkPad T20, T21, T22 and T23 series, from p. 39: product overview and specifications (p. 41), status indicators, FRU tests, Fn key combinations; symptom-to-FRU index (p. 49).
			* FRU replacement notices (p. 56): screw notices and retaining serial numbers.
			* Removing and replacing a FRU (pp. 59-139): numbered procedures from 1010 Battery pack (p. 60) to 3020 ThinkPad Dock top cover (p. 136).
			* Locations (p. 140) and parts list (p. 143), with the model matrix (p. 146), LCD FRUs (p. 157), keyboards (p. 160) and recovery CDs (p. 161).
			* Notices (p. 174).

	* '''About this manual~~''' and '''Introduction''' — the '''strategy for replacing FRUs''' (reinstall the original part if the replacement~~ does not fix the fault; if a machine has both a processor board and a system board, put the first one back before trying the second; remove multi-FRU assemblies one part at a time), how to use error messages, and the diskette compatibility matrix.		== What this manual does not contain ==
	* '''Safety information''' — general and electrical safety, the safety inspection guide, ESD handling, grounding requirements and the laser compliance statement, with the safety notices repeated in every supported language.
	* '''General descriptions''' and '''Related service information''' — restoring the preloaded system, '''passwords''' (including what can and cannot be cleared), and '''power management'''.
	* '''Checkout guide''' — testing the computer, detecting system information with PC-Doctor, and the '''power system checkout''': checking the AC adapter, operational charging, the main battery pack and the '''backup battery''', each with its own measurement.
	* '''Product overview''' — specifications, status indicators, FRU tests and the Fn key combinations.
	* '''Symptom-to-FRU index''' — numeric error codes, error messages, beep symptoms, '''LCD-related symptoms''', intermittent problems and undetermined problems.
	* '''FRU replacement notices''' — the '''screw notices''' (torque and thread-lock rules, which matter on magnesium frames) and retaining serial numbers.
	* '''Removing and replacing a FRU''' — the numbered 10xx sequence, which must be followed in order because later steps assume earlier ones.
	* '''Locations''' — front, rear and bottom views by machine type.
	* '''Parts list''' — FRU part numbers, including the keyboard and LCD part numbers by country and panel supplier.

	~~== What~~ it ~~does not contain ==~~		The manual works at FRU level. It has no schematics and no component values, and a system board is a single part number. The only capacitor it mentions is the "bulging capacitor" hazard in the safety inspection guide.

	'''Module level, and firmly so.''' These manuals name FRU part numbers, not component values. Across a typical ThinkPad maintenance manual the word "capacitor" appears '''once''', in the ESD handling note. There is '''no schematic, no board layout, no parts list below FRU level and no component data of any kind'''. A system board is one line item with one part number.		== What it settles ==

	~~That is IBM's service model, not a gap in the scan~~, ~~and it is why no ThinkPad on this wiki has a component-level capacitor list~~. ~~If you need a board-level repair on a ThinkPad~~, ~~this manual will tell you which board~~ and ~~how~~ to ~~get~~ it ~~out~~; ~~it will not tell you what is~~ on it.		The power system checkout (pp. 35-37) gives these limits: AC adapter output +15.5 to +17.0 V dc at pin 1; battery pack +0 to +12.6 V dc between terminals 1 and 5, discharged if below +11.0 V dc, and 4 to 30 kΩ between terminals 4 and 5 if above it; backup battery +2.5 to +3.2 V dc on the red wire.

	~~== What it settles ==~~

	~~'''All four machines share two machine types''' — 2647~~ and ~~2648 — so the type number does~~ not ~~distinguish~~ a ~~T20 from~~ a ~~T23. Work from~~ the ~~full type~~-~~model on~~ the ~~label~~.		The password section (pp. 26-27) sets out what IBM would and would not reset: a forgotten power-on password can be removed; a forgotten supervisor password has no reset procedure and the system board must be replaced; a forgotten user hard-disk password can be bypassed only with the master hard-disk password.

	~~Note also that [[IBM Mobile Systems ThinkPad Hardware Maintenance Manual~~ (~~April 2002~~)~~]] holds a '''byte~~-~~identical copy''' of this same file under a title that suggests a general ThinkPad volume. There is no such general volume; it is this manual~~.		The screw notices (p. 56) say the screws are nylon-coated, should be used only once, and are tightened by angle (90 degrees past contact for plastic to plastic, 180 degrees for logic card to plastic) or to the torque given in each procedure.

	<pdf> File:IBM ThinkPad T20 T21 T22 T23 Service Manual.pdf </pdf>		<pdf> File:IBM ThinkPad T20 T21 T22 T23 Service Manual.pdf </pdf>

	Download ~~it here~~: [[:File:IBM ThinkPad T20 T21 T22 T23 Service Manual.pdf\|IBM ThinkPad T20 T21 T22 T23 Service Manual.pdf]]		Download: [[:File:IBM ThinkPad T20 T21 T22 T23 Service Manual.pdf\|IBM ThinkPad T20 T21 T22 T23 Service Manual.pdf]]

	== Related pages ==		== Related pages ==

	* [[IBM Mobile Systems ThinkPad Hardware Maintenance Manual (April 2002)]] ~~—~~ the same file under ~~a misleading name~~		* [[IBM Mobile Systems ThinkPad Hardware Maintenance Manual (April 2002)]], the same file under the cover title
	* [[IBM ThinkPad T30 ~~Service~~ Manual]] ~~·~~ [[IBM ThinkPad A20m/p A21m/p A22m/p Hardware Maintenance Manual]] ~~·~~ [[IBM ThinkPad X20 X21 X22 X23 X24 Hardware Maintenance Manual]]		* [[IBM ThinkPad T30 Hardware Maintenance Manual]], [[IBM ThinkPad A20m/p A21m/p A22m/p Hardware Maintenance Manual]], [[IBM ThinkPad X20 X21 X22 X23 X24 Hardware Maintenance Manual]]
	* [[IBM ThinkPad Notebooks - Personal Systems Reference]] ~~·~~ [[IBM ThinkPad Notebooks (A/G/R/T/X) - Personal Systems Reference]] ~~—~~ for ~~identifying a machine from its~~ type-model ~~number~~		* [[IBM ThinkPad Notebooks - Personal Systems Reference]] (machines withdrawn by January 2001) and [[IBM ThinkPad Notebooks (A/G/R/T/X) - Personal Systems Reference]] (A, G, T and X series withdrawn by May 2005), for model specifications by type-model

	[[Category:IBM Service Manuals]]		[[Category:IBM Service Manuals]]
	[[Category:Service Manuals]]		[[Category:Service Manuals]]

Josh: P4 verification: real documentation page - title as printed, part/form number, edition, contents, honest gaps, what it settles, cross-links

2026-09-24T23:17:25Z

P4 verification: real documentation page - title as printed, part/form number, edition, contents, honest gaps, what it settles, cross-links

@@ Line 1: / Line 1: @@
 <pdf> File:IBM ThinkPad T20 T21 T22 T23 Service Manual.pdf </pdf>
-IBM ThinkPad T20, T21, T22 and T23 laptop service manual.
+Download it here: [[:File:IBM ThinkPad T20 T21 T22 T23 Service Manual.pdf|IBM ThinkPad T20 T21 T22 T23 Service Manual.pdf]]
-Download the IBM ThinkPad T20 T21 T22 T23 Service Manual here: [[:File:IBM ThinkPad T20 T21 T22 T23 Service Manual.pdf]]
+* [[IBM Mobile Systems ThinkPad Hardware Maintenance Manual (April 2002)]] &mdash; the same file under a misleading name
 [[Category:IBM Service Manuals]]

Josh: Create page for IBM ThinkPad T20 T21 T22 T23 Service Manual

2026-05-22T09:13:26Z

Create page for IBM ThinkPad T20 T21 T22 T23 Service Manual

New page

<pdf> File:IBM ThinkPad T20 T21 T22 T23 Service Manual.pdf </pdf>

IBM ThinkPad T20, T21, T22 and T23 laptop service manual.

Download the IBM ThinkPad T20 T21 T22 T23 Service Manual here: [[:File:IBM ThinkPad T20 T21 T22 T23 Service Manual.pdf]]

[[Category:IBM Service Manuals]]