Re: [Thinkpad] [tp765L] Power questions

Hi Again David,

As it turns out ~ I was right all along, the pin assignments on the
trapezoid plug of a 760/765 ac/dc adapter are as follows:

Pin 1 ~ Positive
Pin 2 ~ Signal
Pin 3 ~ Negative
Pin 4 ~ Communications Ground

Re the led light, the laptop does a self test when it first power up.

Try this, with the battery in or out, leave the lid closed and turn on
the laptop. You should see the battery charge led light up momentarily
then go off.

Another good tip too is to get into "setup" by means of the F1 button
when you first turn on the machine, go to test and run a diagnostics of
the "system board" If there is anything wrong with any component
attached to the system board, believe me you'll get a red error fru
listing of what needs attention.

Also, you may want to test the battery with a voltage meter.
There's five leads to the batteries; negative, pos 1, pos 2, ground,
and communications signal. The pos 1 or 2 should give some
voltage reading. These batteries are hot-wired like I mentioned
before in a weird configuration (both in series & parallel) in two
difference sub groups for the shear reasons that when one or more
cells inside the pack goes bad, the inside circuitry reroute the remaining
good power to either terminal that isn't affected. This is usually the case
when you see the keyboard led displaying anything less than 100% as
a full charge.

Here's a good resource to check out (technical specs)
ftp://ftp.software.ibm.com/pc/pccbbs/mobiles/765tref.pdf

If you do have that charger led light up when you first turn on
the machine with the lid closed, and the "main board" diagnostics
comes back clean ~ I'm sticking to a bad battery.

Before I forget, another good little gadget is that "quick charger"
that plugs between the adapter and laptop ~ a dime a dozen at your
local auction site. You could definitely use that as a means to charge
your battery, if you get no charge, then that's yet another indication
the battery needs replacement and of course rules out component
failure in the laptop.

One last thing, a lot of people when it came to those batteries at least
in the 760/765 line would easily be fooled into thinking they needed
to replace a battery for the shear reasons that no indicator led or
lcd percentage display, but I learned that these batteries when not
used for a long time, eventually lose all it's power, and sometimes,
just leaving the battery in the laptop with the charger plugged in
wakes it up. For example, I got a large load of "new" batteries from
a guy in Tx that told me the batteries weren't any good because he
tested one after another. As it turned out ~ being new, on in storage
for years, the packs were completely empty. I too thought the batteries
were bad and one night, I inadvertently left on in the laptop plugged in.
The next morning, to my surprise, the battery was charged to 100%.
Surprisingly, I took the next new pack and snapped it in, it actually took
20 minutes to finally get a detect from the lcd, and of course a full charge
after full charge cycle ~ I made a killing on those considering I bought
into them for $2 each and sold them at $45 with 90 days guarantee.

Justin

David Ross wrote:

> > There is a LCD battery meter on that machine. If it does not show
> anything,
> > you can bet the battery is gone
>
> Thanks Bruce (and Justin). There is every reason to believe that the
> battery is dead (the machine was bought refurbed 2-3 years ago...)
>
> I'm still concerned that the external charge light (leftmost light of the
> three on the back of the hinge) doesn't come on at all.
> On my machines this comes on even with a dead battery, unless there is
> something else wrong with the charging system. I would hate to suggest that
> my colleague spend $60+ on a new battery, only to learn that it won't charge
> because of a machine problem.
>
> - David R.
>
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Received on Fri Sep 5 11:48:56 2003