(Resent because of misspelled tag, sorry)

I think it is only playing dead

Maybe some brilliant person here have a clue, I have exhausted my clues on=
 this...

I have tried to change cells in old battery packs for the laptop Compaq=
 Armada 7730MT.
Theese packs have built in electronics, a ridicoulous amount of SMT=
 components including lots of IC.  I know they are for protecting the pack=
 from being under and overcharged, but still seem more than plenty.

Anyway, after changing the cells, the pack still plays dead; do not take=
 charge, and do not deliver after manually directly charging the cells=
 either.

This is strange!
Are theese battery packs designed to play dead after cells are replaced?
(So Compac can sell new expensive packs)  Or is it just a design flaw?

Anyway, any ideas to get them working?

Seems like all electronics is shut down; I can nowhere among the chips find=
 any supply voltage.  Maybe it needs to have a small voltage from the cell=
 at any time to keep powering itself.  How to start it then?

I tried to short the battery plus to plus connector pole (minus is common)=
 and then the pushbutton activated built in LED battery charge meter is=
 working, but when placed in the laptop, the laptop starts up, beeps some=
 times and then shuts off...

The connector to the laptop have two large pins, plus and minus, and then=
 four small pins terminated with 10 ohms resistor, apparently some signal or=
 communication, maybe serial.  Maybe it needs to be talked to first time=
 after power up, and get it loaded with battery parameters etc?

I really got no idea about how to continue now.


This have happened two times now both a Compaq Armada 7730MT:

First time a friends Compaq gave up, letting the smoke out of the power=
 supply and a cap on the main board, replacing them made it live up, but the=
 battery pack still dead.  It had been dead for a while so some cells have=
 shorted so I replaced them but the pack was still dead, so I reckonned the=
 cirqiut board somehow got damaged by the power supply, or it broke taking=
 the supply with it.

Today, I replaced the cells in my girlfriends laptop battery pack, and now=
 that pack is dead too...

Regards
/Morgan=20
Morgan Olsson          http://www.morgansreglerteknik.se
morgans.rt@telia.com, tel +46(0)414-446620, fax -672324
Morgans Reglerteknik AB, H=E4llek=E5s, 277 35 KIVIK, SWEDEN

--
http://www.piclist.com hint: To leave the PICList
mailto:piclist-unsubscribe-request@mitvma.mit.edu