Battery Drain to fast, issue with MESA?
My iPad Air 2 start discharging to fast. After few weeks not touching was completely dead. I was thinking that battery casue that issue so I order brand new and replace.
What I observe, measure:
- Tablet is working but my issue with battery drain still present. 1-2hour and its 0%
- Charging current is 2-2.5A
- Touch ID is not working. Not sure if was working before. Home button function working
- Touch screen is working but during charging seem to be less sensitive
- All other components are working (display, charging, speakers, cammeras, buttons, wifi, LTE,..)
- current consuption when tablet is off is 0.65mA - I think is OK.
- when Screen is ON temperature is OK. When Screen is Off then the mettal part in left down corner of dispplay start to be extremly hot
- Also STD9307 start to be extremly hot. DOnt understad since this is GND accordign schematics. Looks like shortcut in case that Display is Off.
- I Measure MESA component (U4770). PPVCC_MAIN_MESA = 3.7-3,8V. When Screen is OFF the PP11V3_MESA_FILT = 11.3V, PP3V1_S2R_MESA_FILT = 2.5V (accordign schematics should be 3.1V), PP1V825_S2R_MESA_FILT = 1.82V.
- When Screen is ON then PP11V3_MESA_FILT = 0V
I measured MESA since shoudl be related to the Touch ID and Touch ID is not working. So thinking that causing my issue with battery drain.
Does somebody know how MESA shoudl works , when ?
if Measured voltage PP3V1_S2R_MESA_FILT = 2.5V is OK?
what casue that STD9307 is extremly hot ?