Dead i7 intel
Not as detailed as some of my other stuff but I have another that will need a cuppa or two....coming.
So its a dead device no history.
Nothing on charger and no pc comms.
After testing vbat, vdd Main and Boost it was determined VDD Boost was shorted.
I applied Rosin near the Fingerprint FPC, as the job come in after screen fuckery.
The original screen had ripped flex so it makes sense.
C3828 showed under rosin and was removed and short was one.
There was still no Touch ID so I measured the voltages on the FPC for touch 1v8 signals, 2v75 , enable etc.
To do this efficiently I Forced DFU the device and then I can measure the voltages on the FPC without the flex attached, in DFU they stay ON. Otherwise you will only catch a glimpse at boot time and when no screen is detected via i2c they switch off right away so in DFU they stay on to test properly.
I had no 2v75 voltage present so I probed 1v8 (DCPS) on the enable and got the 2v75 output, the 1v8 pad was burnt out under U3801. This is the LDO Enable just a 1v8_touch voltage.
I jumped a 1V8 touch/enable and we had it outputting the 2v75 to the FPC.
Touch ID now fixed.
The battery was not charging and no data was available in 3utools, testing showed a bad BAT SWI resistor near the FPC.
R2201 was replaced and all is working as it should be, Touch ID, Charges, Battery Data available and PC Comms.
Quick test using any screen to detect the Touch ID via 3utools, even though incorrect serial it shows the path for detection is now working.
Once the original home Button was in place the serials matched.
The VDD BOOST short caused No Boot, No Touch ID, No Charging and No PC comms.
Now for the NO IMEI, I have a set of steps for this stuff and after checking Data Info, BBPMU outputs and Modem voltages I was steered towards the next stage which was Transceiver and RFFE!!!!
XCVRO_RF was tested and needed a REBALL, update and IMEI was back.
Not forgetting the cams.
Rear cam was not being detected and needed J4501 pins re-soldered and both cams were now working as seen in the image previously for Touch ID Detection.
Activated the device to Apple ID and thats that.