Particle Photon Blinking Orange Continuously

I have a project run on a Particle Photon, and today I noticed the Photon constantly blinking orange, about once per second, staying off for about half a second each time.

Constantly blinking orange isn’t in the documentation as a troubleshooting mode. Has anyone ever seen this before or know what it means? No cyan was involved.

This Photon has had trouble connecting to the cloud before, but was otherwise working alright for the past few days.

When I plug it into my computer via USB it immediately connects to the cloud, breathing cyan. It is running firmware that puts it into deep sleep mode, so a few seconds later it went to sleep which is fine. Normally I can wake the device up and put it into safe mode then it will remain in safe mode, connected to the cloud. In this case trying to put it into safe mode doesn’t work - it flashes cyan as if it were in safe mode but then goes into deep sleep.

Trying agin to put it into safe mode results in a white flash followed by a fade to orange. This flash and fade becomes faster over time, increasing in speed.

I just recently got an order for a number of devices based on this design, which I though was working alright. So discovering this kind of erratic, undocumented behaviour could be a real problem problem for me. I appreciate any help you guys can offer.

p.s. this is the diagnostic message sent to the cloud upon connection, in case it helps:

Blinking orange isn’t a standard color combination. However, my guess is that it’s power-related. When the Photon boots, it blinks white at least once. However, when there is insufficient voltage or current, the white shows up as a red or reddish-orange color. My guess is that’s the orange, then the device enters brownout power down (LED off), then the cycle repeats.

Thanks for the answer.

I measure the voltage of the NiMH battery (4 AA cells) at 4.75V. The cell voltages read 1.195, 1.172, 1.188, 1.195 which I think is normal enough. So if this is power related I would like to know more about the Photon’s power needs. As far as I know the data sheet suggests that between 3.6V and 5.5V is fine.

I tested with an ammeter inline, and the voltage while booting. Although the voltage of the battery pack looks ok, it provides only about 88ma and the voltage droops to about 2.23V.

So I guess that settles it, it must be a brownout from a damaged battery. Thank you for the help!