I have just had the problem of a dead touchpad.
I have been posting on the unofficial board, but thats now been closed, as eyeballer has moved to the official board.
nothing I did would bring the bloody thing back to life.
In the end I took it apart, measured 2.85volts on the battery, which is way too low.
As an experienced electronics engineer, I felt able to play around.
I took out the battery, gave it about 3 or 4 hours @1Amp charge, the voltage then went upt to 3.56 volts, so above the 3.2v low level
I always seemed to get a strange effect of sometimes the DVM across the battery would read a sensible value, at other times it was zero.
is there some circuitry inside the battery ?
Anyway, I drilled a very small hole in the case (2mm diameter), and attached a wire to the battery +ve, and made a connector so when I clicked the case back together, I could measure the voltage, and externally charge the battery, to kick start it again if needed.
I am using the -ve supply on the usb micro socket ( that way I only need a single small hole to connect).
so, I measured the voltage with the thing re-assembled, and its zero volts ( bugger !, maybe i have done something wrong).
As a last resort, I connected externally -ve wire to the usb plug screen metal part, connected +3.5volts from a power supply to the hole I made, and pressed the ON button.
Voila !!, the touchpad came to life boots and shows the battery at 61% full.
I cant believe that the charging circuitry measures the battery voltage, and if its gets too low, refuses to charge, that would be just plain dumb !!!!!
, but maybe my applying that external 3.5 volts, enable the charging circuitry to wake up !!!!
I have taken photos of my mods, and will post them in a few days.
I am coming to the conclusion that hp really screwed up with the battery charging/detection circuitry, and thats why we are seeing so many problems.Maybe thats why hp killed the thing !!!
Edited by mikestefoy, 29 June 2012 - 03:59 AM.