On Sun, 30 Jan 2011 22:54:53 +0000 (UTC), bz
wrote:


We tried another battery and psu from a different 1545 (that had a
broken DC socket) but that didn't change anything.


The laptop 'talks' to the power supply over the central lead (there is a
small computer IN the supply or a resistor that tells the computer the
wattage of the supply).

OK, I guessed it did something clever like that (or I'm not sure how
else it could 'know').

If that center lead is broken, the computer can run from the supply but
will not allow the battery to charge.

OK.

The flashing power indicator usually indicates a failing or failed battery
pack.

Well I'd say it's not yer typical 'flashing' (I have seen that too)
but what looks like more of a fault code.

I have fixed many 'bad' supplies by cutting the 'broken' spot out of the
cord.

Same here, even if only ass an experiment or a kludge for myself.

It is usually where the cord gets the most flexing.

Same with most flexy cables. I've salvaged a good few Dyson cleaners
for no more that lopping 3" off the lead at the cleaner end. One was
at the plug end though so that DC05 cost me 50p for a plug (cleaner
was off Freecycle). ;-)

finding it, cutting and splicing the cord to fix it can be challenging.

Bread and butter to me luckily (I built / ran a mobile disco for 8
years).

I usually cut a few inches from the power plug and check with an ohm meter.
If I was lucky, that is the end and some work with a razor knife, soldering
iron and hot glue and you are back working.

Yup. A bit of a push-n-a-wiggle will highlight a lot of problems. ;-)

If it is at the power brick end, you will probably have to crack the brick
open with a screwdriver and solder the cord into the brick.

Done that as well. Neat hacksaw cut along the seam normally gets you
pretty close.

Sometimes, I end up with repairs at both ends and a cord that is much
shorter, in between.

;-)

Hint for all laptop supply users:
NEVER NEVER NEVER wrap the cord tightly around the supply, bending it
sharply near where it exits the supply.
Coil it loosely and let it look messy.

Seconded. The number of times I see that being done. Apart from
knowing what it can do to the conductors it's not 'seamanlike (same
with those who coil rope round their hand and elbow).

NEVER NEVE NEVER put a aharp bend in the cord near the plug nor near the
brick.

Yup, loose coil leaving it as straight as possible then coil (although
I should imagine / hope that was egg sucking training to many here).
;-)

Cheers, T i m