[ltp] A21p power supply question

[Tod Harter]

Well, to the best of MY knowledge, and I've handled a lot of different models 
of machines over the years most thinkpads have essentially the same external 
PS, all that varies is its output rating, so for instance the PS for my old 
380ED and my A20p have the same connectors and the same voltages, just the 
380 took less juice. So you might kill the 380's power brick by trying to run 
an A20 with it, but it probably wouldn't be an immediate kind of thing, it 
would just get hot and burn up after a while trying to supply the extra 
amperage.

To be even more specific I am pretty sure that the I and A series machines all 
use the identical same supply with the exact same output rating. I know that 
my A20p and one of the more recent I-series machines (one from the last 3-4 
years, I forget the exact model) were the same brick. I have seen the bricks 
for A30's and they also looked identical (but I didn't actually check it 
out). 

I also cannot see how damage to the power brick would cause only a failure to 
charge the battery. I guess its possible, but those bricks are nothing but a 
transformer and a DC power supply. Not much can really go wrong, and the only 
damage you can really do to them is to overload one. I'd get a voltage meter 
and make sure the brick outputs the specified voltage and that it doesn't get 
exessively hot, then I'd try running the machine off another brick with the 
same ratings and see if your battery charges. I'm betting the battery itself 
is just bad. If its more than a couple years old it could have gone belly up. 
Lithium Ion batteries tend to die suddenly with little or no warning. The 
usual scenario is the battery capacity gradually decays from its new 
condition to 50-70% of that and then one day it just doesn't work AT ALL 
anymore. I had one fail the other day and it went from working perfectly to 
dead as a doornail in 1 second flat. 

On Saturday 22 February 2003 07:25 pm, Justin Banks wrote:
> Hello -
> 	A friend of mine has an A21p, and recently another friend with an
> i-series asked him for some help with his keyboard. The guy with the A21
> plugged his power supply into the i-series, because it happened to be
> handy, and proceeded to fix the keyboard problem. The problem now is that
> while the A21 will run just fine on wall power, it doesn't seem to recharge
> the battery at all anymore. Does anyone have any idea where to start
> figuring out WTF is going on here, or is it just time for a new P/S ?
>
> TIA,
>
> justinb

-- 
Tod Harter
Giant Electronic Brain