I had the 16 V setting right... but when it came to my Polarity setting... there was the setting on the AC Adapter i could go by, or what was right above my power input to the laptop... Only thing was, is there was no indication of how it was sopose to be. - to + or + to -. depending on how you look at it.. Well in both a haste of wanting to test it and having to guess via the laptop .... I plug the thing in with reversed polarity..... !POP! *i unplug it within 1 second* and it begins to lightly smoke.... i almost crapped myself thinking that i just ruined my laptop.. But it turns out, i turned it on via battery power..... everything seemed to work perfect.... i plug it into the wall with my AC adapter, and it worked perfect....
Most
IBM laptops, like most modern laptops, have
polarity protection. This consists of a diode across the DC input. Where the power goes in, there's a
picofuse, a very small fuse that looks like a liitle green resistor. Downstream from that is the diode. Normally, the diode is reverse-biased, an open circuit. In the event of a polarity reversal, the diode becomes forward-biased, an electrical short. This draws sufficient current to blow the fuse, protecting the rest of the circuit.
What you now have is a blown fuse and, possibly, a shorted diode--thought it's possible that the diode survived, just got hot--hence the smoke. You will need to find the
PDF service manual on the IBM site (I can't do
all your work for you
) for disassembly instructions and replace the picofuse, then check the diode. Even the cheapest (~$10 at a hardware store or
Radio Shack) volt-ohm-milliammeter (VOM) will do this just fine. You need to find a full-line electronic supplier in your area, and you will have to buy 5 picofuses to get one (but then you will have spares, right?). If you don't know what I mean by full-line supplier, ask your local TV repaiman where he buys his parts locally, or ask a computer repair shop, or ask either one if he will sell you a picofuse of the correct rating for a price.
Of course this presupposes that you are able and willing to do a little mechanical disassembly and soldering to save a ton of money.
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