I use external harddisk(connected via USB with its own power supply) to boot into dietpi on my raspberry pi. It works okay for a day(even with multiple reboots and poweroff). But the next day RPi sends no power to usb ports and so it doesn't boot.
When I use SD card to boot it works. Ethernet port works and I'm able to SSH. I've plugged my external drive using the USB adapter to another computer and I can confirm that it is working. I am using the official power supply (2.5A 5.1V).
If I try to boot after keeping the RPi off for more than 1 day from the external HDD it works again! But this repeats everytime. I can't understand this peculiar behaviour of my rpi 3b.
I have also set max_usb_current=1 in boot/config.txt but still no luck.
Here is the output of some of the commands I ran after booting with sd card on raspbian:


pi@raspberrypi:~ $ lsusb
Bus 001 Device 003: ID 0424:ec00 Standard Microsystems Corp. SMSC9512/9514 Fast Ethernet Adapter
Bus 001 Device 002: ID 0424:9514 Standard Microsystems Corp. SMC9514 Hub
Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub

lsblk: (with external HDD connected)

pi@raspberrypi:~ $ lsblk
mmcblk0     179:0    0 29.8G  0 disk 
├─mmcblk0p1 179:1    0  256M  0 part /boot
└─mmcblk0p2 179:2    0 29.6G  0 part /

dmesg | grep usb (A lot of over-current change errors messages)

pi@raspberrypi:~ $ dmesg | grep usb
[ 1039.172044] usb 1-1-port2: over-current change #4012
[ 1039.430051] usb 1-1-port2: over-current change #4013
[ 1039.688057] usb 1-1-port2: over-current change #4014
[ 1039.946054] usb 1-1-port2: over-current change #4015
[ 1040.204102] usb 1-1-port2: over-current change #4016
[ 1040.461910] usb 1-1-port2: over-current change #4017
[ 1040.720016] usb 1-1-port2: over-current change #4018


# For more options and information see
# http://rpf.io/configtxt
# Some settings may impact device functionality. See link above for details

# uncomment if you get no picture on HDMI for a default "safe" mode

# uncomment this if your display has a black border of unused pixels visible
# and your display can output without overscan

# uncomment the following to adjust overscan. Use positive numbers if console
# goes off screen, and negative if there is too much border

# uncomment to force a console size. By default it will be display's size minus
# overscan.

# uncomment if hdmi display is not detected and composite is being output

# uncomment to force a specific HDMI mode (this will force VGA)

# uncomment to force a HDMI mode rather than DVI. This can make audio work in
# DMT (computer monitor) modes

# uncomment to increase signal to HDMI, if you have interference, blanking, or
# no display

# uncomment for composite PAL

#uncomment to overclock the arm. 700 MHz is the default.

# Uncomment some or all of these to enable the optional hardware interfaces

# Uncomment this to enable infrared communication.

# Additional overlays and parameters are documented /boot/overlays/README

# Enable audio (loads snd_bcm2835)

# Enable DRM VC4 V3D driver on top of the dispmanx display stack




Please help me resolve this issue. Thanks :)

Update: I checked and found that there is 5V being supplied to USB ports(measured with multimeter between P1/P2 to P27) and I still don't know what's causing the problem. Even regular USB flash drive is not working. How can I diagnose the issue?

  • 1
    May be the external power supply is one part of the problem. Some rare devices ignore the USB spec and if connected to a power supply also send the power upstream to the USB host - in your case the Raspberry. I don't know what protections the Raspberry has on USB power level but if it has some resettable fuse the behavior you observed would be possible.
    – Robert
    May 19 at 20:25
  • Okay so I measured voltage between PP3-PP27 as suggested here: raspberrypi.org/forums/viewtopic.php?f=28&t=110164 and I found out for me it's fluctuating between 0.01V - 0.06V using the official power supply. I think that's too low? Maybe the power supply is faulty?
    – Kiran
    May 21 at 6:18

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