[SPARCbook] Power problems

[Liam]

Hi,
     I've got a problem with my SB3 TX  which I've made worse and don't know
what to do next.
   The original problem was that it stopped working when the charger was
plugged in. It would / will charge the battery (which obviously runs down
quickly) when plugged in and not being used, but would then only run on the
battery with the charger still connected.
   I have tried an original Tadpole charger, a HP one and my own bodged one
with no result. They all, however, work on my SB3, SB3XP, PowerLite and
PrecisionBook. (This might sound greedy, but I like the little beasts!
Something about unusuality!) The TX being the higher spec. of the lot, I'm
disappointed that this is the one that gave up.
   On guesswork, I have checked voltages going to the battery terminals with
the charger connected; to both the internal battery and the terminals of the
external battery (even though I don't have one) and have 5v and 12v  (-ish) on
some terminals.
   Thinking myself clever by previously identifying damaged components on one
of the boards of my XP, then finding out the values (straight from Tadpole, no
less!) and finding someone to do an economical repair, I took the whole thing
apart to examine the circuit board tracks. I am certainly no expert,  but
there was no burning damage evident anywhere. At one stage, though, while
poking and pressing connections with the charger plugged in, I'm sure I
smelled burning. My wife says she didn't....but we don't always agree on
things (especially computer related), anyway.
   While I had the whole thing apart, (I can explain why I did it...I've got a
Sun Ultra 5 that I had to change the NVRAM in, and got inquisitive) I took the
'SnapHat' battery off the NVRAM. I know this was not a clever thing to do. I
know that I will probably end up putting the thing into a shop for someone who
may understand the power problem to see, but is unlikely to recognise any
printenv stuff. (Unless I want to pay a real fortune).
   Any ideas would be gratefully recieved. I would really hate to write this
box off.
                                                                             
                                                               Yours in hope,
Liam