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<snip>... so I use a lab power supply, but all I get is the "critical low-battery error" and sometimes I manage to get to the bios setup screen. If I buy an original adapter, will it work?
Short answer, maybe. Longer answer: http://forum.thinkpads.com/viewtopic.php?t=60037
On that T23 I described, the only time that the 0190 error goes away is when I have a known good battery installed. Still haven't gotten around (or worked up the nerve) to plug the "dead" battery into another one of my T23s and see what that does. Using a lab supply, as long as it can supply at least 4 to 4.5 amps at 16VDC, should be fine. My guess is that you will also need a good battery to get past the critical low-battery error.