My sparkcore chip antenna was disconnected from power flashing a program. Now the led loops flashing rapid yellow, rapid white, solid white, rapid white. It’s become unresponsive to firmware flash now tested and confirmed ability to firmware flash on my ufl core. Any ideas?
No worries!
Hmm… It’s weird why your core is behaving so (sounds like a rainbow sequence when you connect via Tinker app).
What you can do is to simply perform a Factory Reset (hold down both button, release the RST and wait for ~7-10s till you see flashing white)
That will bring the core to Blinking Blue and you can now send Wifi credentials via USB or App.
Give it a shot!
It never breaks the cycle, just keeps going even after trying factory reset.
Are you able to perform a factory reset?
Only release the RST button and hold on the Mode button. What happens while you are trying to do this?
When I hold down mode and press reset it turns off the led, releasing only the reset button I get yellow flashing for 8 seconds, rapid white 5 seconds, single white pulse for a second, then rapid white 5 seconds again. This is the same pattern I get constantly no matter what.
Able to Vine or youtube to video this down?
It’s my first encounter of the core becoming broken. Sounds like the factory reset firmware got affected as well.but shouldn’t be the case.
Do you use DFU? We can attempt to flash a new firmware over and see how things go!
I have flashed firmware before but it is no longer responsive to trying to flash.
Here’s a video the Yellow flashing appears green in the video but I assure you it’s yellow.
root@alpha:/home/server/Downloads# dfu-util -l
dfu-util 0.7
Found Runtime: [413c:8187] devnum=0, cfg=1, intf=3, alt=0, name=“UNDEFINED”
root@alpha:/home/server/Downloads# dfu-util -d 413c:8187 -a 1 -s 0x00020000 -D factory_firmware.bin
dfu-util 0.7
Filter on vendor = 0x413c product = 0x8187
Opening DFU capable USB device… ID 413c:8187
Deducing device DFU version from functional descriptor length
Run-time device DFU version 0100
Claiming USB DFU Runtime Interface…
Determining device status: state = appIDLE, status = 0
Device really in Runtime Mode, send DFU detach request…
Resetting USB…
Lost device after RESET?
root@alpha:/home/server/Downloads# dfu-util -l
dfu-util 0.7
Found DFU: [413c:8189] devnum=0, cfg=1, intf=0, alt=0, name=“UNDEFINED”
Hmmmm… Your spark core isn’t showing up correctly and this is usually a DFU driver problem and the flash might not be successfully
probably worth mentioning the thing feels like it its going to combust. I dont have an IR thermomiter but with a regular digital one I got over 110 F I think I may have broken it when the power cut durring flashing.
I guess there might be some corruption to the external flash, internal flash etc. but not to the extent of burning in to flames. 
Did you used DFU successfully before?
We need to see:
Found DFU: [1d50:607f] devnum=0, cfg=1, intf=0, alt=0, name="@Internal Flash /0x08000000/20*001Ka,108*001Kg"
Found DFU: [1d50:607f] devnum=0, cfg=1, intf=0, alt=1, name="@SPI Flash : SST25x/0x00000000/512*04Kg"I have used DFU before no issue now I just get the error where the device ID changes and the “Lost device after RESET?” happens
So it sounds like you are not able to put the 
core in DFU mode as well!
Cos device id doesn’t just get changed due to a power cut. The device shown is most likely something else connected to your machine.
Seems like there’s limited resolving techniques we can with DFU not working…
Your best bet would be to try out factory reset/DFU a couple of times and hopefully the core does a clean and loads the factory-reset firmware.
@zachary needs to hear about this really!
I’m sure you’re getting this right, but just in case: When you get the rapid white flashes RELEASE the button.
OK, here’s some helpful info based on what I can tell from this thread.
- The Spark Core will always have USB vendor and product ID
1d50:607f. @Kellycas when you ran dfu-util, you were working with413c:8187which according to this page is a Dell DW375 Bluetooth Module. Since, in the snippet above, you set-a 1and thedfu-util -loutput only includedalt=0, then you didn’t actually touch the bluetooth module with that command anyway. - It looks from the video like the Core is performing factory reset over and over again even though you’re not touching it. This might mean the MODE button is stuck down or shorted so it acts like it’s stuck down.
Try running dfu-util -l after the Core has started flashing yellow, but before it starts flashing white and let us know if there’s any -related output.
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I have got no news, I have tried several times to get dfu-util -l to see a different device, I have jumped between three computers, several cables and I am at a loss.
Did you put the core in DFU mode (blinking yellow)? Maybe it sounds trivial but it might slip our mind.
Also, open up the device manager and see if the core is listed when in dfu mode. It should appear unless the firmware it’s on now is really screwed.
Post back when you have another attempt! I’ll star this thread and follow up as soon as I see updates 
