Motorola Moto X Force Troubleshooting Manual page 43

Debug Procedure
• Generally the first step to troubleshooting a no turn on PCB is to look at its boot
current. A blank board (no software flashed yet) will normally draw about 80mA at
a constant level.
• Also it is helpful to find out what level of functionality is available. These distinct
modes were observed:
1. Blank Flash mode
• Normally will enter this mode for a newly built PCB.
• Can be forced by shorting debug connector as shown in later slides.
2. Fastboot mode
• Normally will enter this mode after flashing bootloader into newly built
PCB.
• Can be forced using volume down key during bootup
3. Full Power up
• Will enumerate to PC as Motorola Network device and ready for board
test.
• Failed boards will be able to achieve one of these modes but fail to get to the next.
This bit of information is useful for debugging.
• Start with the phone off, then plug in the USB cable. If the phone does not turn on
when the USB cable is inserted, there is most likely an issue with the connector.
• If the current is abnormally high for a blank board, the root cause is most likely a
short. Going through the power on sequence is helpful for finding shorts, it is
shown on the next page.
MOTOROLA CONFIDENTIAL
Moto X Force/DROID Turbo 2
BASEBAND TROUBLESHOOTING GUIDES