KiwiSDR not powering on after power off
I powered off my KiwiSDRs yesterday when we had a power outage. I didn't perform a shutdown first via the web interface. All but one came back OK:
When I applied power, I could see a blue LED on the BBG flash for an extremely short amount of time, some web searching suggests this is the over-current regulation circuitry on the BBG taking action.
I removed the KiwiSDR from the case, and saw the same thing, also tried with another power supply.
I then removed the KiwiSDR PCB from the BBG PCB and powered just the BBG via the micro USB connector, it came up normally and I was seeing the cylon LED flashing of the IP address eventually.
As a test, I then plugged the KiwiSDR PCB back into the BBG and briefly powered both from the micro USB connector (yes, I know... I said briefly) and the BBG started to come up normally before I powered off.
Powering both boards again from the 5V jack on the Kiwi, and using the Troubleshooting the KiwiSDR PCB guide:
5V IN: 5.3V
5VE: 5.3V
5V: 0.68V
3.3V: 0V
1V: 0V
1.8V: 0.03V
3.3A: 0.1V
3.3G: 0.5V
3.3GPS: 0V
I assume the 5V line is low, and 3.3V zero, because the GGB is in some sort of safety/overcurrent protection mode?
I don't see any evidence of obvious damage on the KiwiSDR PCB, nothing felt warm. Any suggestions how to proceed next? Any additional measurements to take?
Comments
What are you using for your external power supply? How much current does it deliver? Have you tried another supply? The KiwiSDR can draw up to 1.5A when starting and you should account for a headroom of up to 2A
http://kiwisdr.com/info/#id-power
When the single blue LED flashes quickly at power on it's not over current protection. It's inrush low voltage or slow waveform rise time protection.
Try the power cable from one of your working Kiwi and it will probably work. Figure out what's different with your other cable causing the voltage sag (e.g. wire gauge too small, cable too long).
I took the power supply from this KiwiSDR (which worked fine before all this started) and connected it to known good KiwiSDR, and it comes up fine.
I took the power supply from that working KiwiSDR, and used it with this one, the BBG booted, but when the KiwiSDR software came up, the webpage reported "No Kiwi hardware detected".
I got yet another power supply, one of the white Apple chargers that works great with KiwiSDRs, and it does the same thing - "No Kiwi hardware detected"
5V IN: 4.86
5VE: 4.78
5V: 4.70
3.3V: 3.40
1V: 1.00
1.8V: 1.80
3.3A: 3.29
3.3G: 3.30
3.3GPS: 3.29
I got another USB charger with a similar power capacity, and the voltages are pretty much identical.
I got a 5V 4A power supply I've previously used with a KiwiSDR as well as a Raspberry Pi, and I get the short blue LED flash.
Something seems to be wrong with this KiwiSDR board? It seems like something is loading down 5V more than is typical.
All the voltages are normal except for 5VE, coming from your supply, and 5V, which comes back from the Beagle after going through a simple FET switch from 5VE. 4.78/4.70 is just too low.
Since your power supplies seem to have enough current capability it's got to be a cable with too much I^2R drop. Too much resistance and/or small wire gauge causing voltage at 5VE/5V to be too low. What are these voltages on a Kiwi that works using the same supply/cable?
I took the power supply/cable from the bad (serial 3615) Kiwi and using it with the good (serial 4759) Kiwi:
VIn:4.88
5VE: 4.82
5V: 4.76 (all other voltages fine/not relevant so for brevity I will skip them)
The Kiwi still works fine.
Extra data:
I took the good KiwiSDR (serial 4759). With it's power supply and integrated cable I get:
5VIn: 5.00
5VE: 4.93
5V: 4.88. (all other voltages fine/not relevant so for brevity I will skip them)
That *same power supply/cable* on the bad KiwiSDR (serial 3615) results in a "No Kiwi hardware detected." message when trying to access it (of course the Admin page comes up fine). Here are the 5 volt voltages:
5Vin: 5.00
5VE: 4.94
5V: 4.86. All 3.3, and the 1.8 and 1.0 volt supplies are as you'd expect.