On Tue, 16 Sep 2008 18:20:52 -0700 (PDT), wrote:

Need to start by finding out what's at fault. You could measure the v
across the battery while its on the charger (and while its off it) to
see if the batt's receiving power, but I suspect its not a dead
battery - if it was it would generally run direct off the charger.

Depends, my iPAQ threw a wobbly and wouldn't switch on, no normal
indication of charging, wouldn't work when connected to the charger, tried
soft and hard resets but it would just sit and make a quiet "click" every
few seconds.

It has a Li ion battery, these have "smarts" inside them as you really
don't want to overcharge 'em or discharge them too fast. Li fires are not
nice and with current battery technology virtually impossible to put out
as the oxygen required is already in the battery.

Anyway I just left it "on charge" and several hours later it spontaneously
sprang back into life. I let it charge fully according to the display and
started using it again, next day it "died" again so I just left it "on
charge" again and it came back. Since then it has worked fine,
9months.(*)

I suspect either the "smarts" got confused about the charge state of the
battery or maybe the protection circuit got triggered and letting it
"charge" then cycle a few times has reset one or both.

Maybe the OP can try just leaving it "on charge" for a day or three and
seeing what happens.

(*) I used to power/charge it from a generic PDA holder in the car. I
suspect that was the root cause of the problem as the battery would get
rather hot with that. I don't do that now only use HP supplied mains
charger or USB sync stand or a TomTom supplied car device intended for the
Li battery in a bluetooth TomTom GPS Rx.

--
Cheers
Dave.