Xperia Arc S - battery drain in OFF state - suspect hardware
my problem is as shortly described in the topic.
The device drains between 50-190mA in an OFF state depending on the voltage applied.
I used a lab power supply to check it.
The procedure to measure it is:
0) perform repair using PC Companion - the device is completely clean
Android version: 4.0.4
It has been upgraded from its factory version quite some time ago.
The drain problem started long after the upgrade.
1) Installed (just for formality): Battery Widget, Battery Stats Plus, OsmAnd, GPS Test, Total Commander
- the rest is usual bloatware that installs itself
1) switch off all possible functions (plane mode, WiFi OFF, BT OFF, ...)
- no alarms, no calendar notifications
2) power down the phone
3) take out battery, SIM card and SD card
4) connect power supply directly to ± battery connectors on the phone
5) no other cables connected (neither the battery)
6) apply voltage 4.2V (190mA) -> 3.0V (33mA) in 0.1V steps
Let me stress it again - the phone is in OFF state - no power button pressed, no attempt to boot it.
At this state I would consider 10mA normal, but definitaly not 200mA.
I have done a bit more measurements, but I don't think it is of use now.
As I mentioned above, the problem started suddenly, long after I upgraded to a newer OS version.
I noticed it since the phone started heating, which I could feel in the pocket.
Now, a bit about the heating. It seems that the source of it is a chip that I have identified as a Flash memory.
It sits around the top left under a metal shield when looking from the back of the phone,
after unscrewing the plastic mid-part. It is worm even in OFF state (no charger, just battery).
It gets very warm when the phone is ON and "unpleasantly" warm when there is some activity
(I actually played with the camera).
Otherwise the phone is fine. I haven't noticed any problems with it.
I use it as a navigation, SD card and SIM inserted, but no service (I mean the SIM card is inactive).
Now the actual question - is there a SW way (I mean without desoldering anything) to possibly
correct this problem? Unfortunately my suspicion is that some power management component
must have failed and it keeps delivering power.
Any help will be appreciated. It is still quite a nice device.