Dim D7 LED and no other lights


#1

I came back to my Photon after not using it for about a week and went to plug it into my computer. Once I plugged it in, the only LED that came on was D7, and it was a very dim blue.

None of the LEDs are on, and I’ve held down the buttons trying to achieve a magenta color.

I tested the voltage between 3V3 and GND and got 3.34 volts.

Any idea on what the problem could be?


The dimmed D7 LED of death
Photon recovery using JTAG, "Cannot read memory"
#2

Holding down both buttons won’t do anything other than turning off the power. Try holding the setup button and press (don’t hold) the reset button. See if that works.


#3

Nope, it didn’t do anything.


#4

with power applied, what does the RST pin measure with respect to GND? When you observe this measurement and press the RESET button what happens?


#5

When I measure across RST and GND, I get 3.32V, when press RST, it starts going down to 0V until I release the button, then it goes back to 3.32V.


#6

Ok great… so it sounds like your unit is not stuck in reset.

Also if you are trying to get into DFU mode and do not see the magenta or yellow RGB LED, your bootloader is not running correctly.

Do you have access to a JTAG programmer?


#7

I do not have access to a JTAG programmer.


#8

Just to confirm, you are not able to enter DFU mode?


#9

That is correct. I can not enter DFU mode.


#10

@BDub
Here you go.


#11

Ok normally I’d say great, but that’s a bummer. Something else that could be happening is an ESD event might have damaged the processor, preventing it from executing the bootloader. Would you please write in to hello@particle.io and ask for a replacement? Reference this thread. Thanks!


#12

Email sent. Thanks!


#13

I have the same problem with my photon, what i can do?


#14

So you can’t get into either safe mode, nor DFU mode?


#15

Yes, i can’t


#16

If you have another device (Core/Photon/P1/Electron) you could try this - https://github.com/m-mcgowan/embedded-swd

It’s still in beta but it can be used to revive devices. This will try to fix things so that you can get into DFU mode.


Photon RGB LED does not turn on at all even in Safe mode
#17

Yes i have an electron and a core too i will try


#18

I would try on the electron first, since that’s also a STM32F2 device.


Photon unresponsive, steady blue light
#19

i tried it and my electron and photon just turn more intensive D7 led


#20

What was the output - did the tool report success?