Reviving Moteino after applying 9V in reverse

[joelucid]

Ok, Felix recently said it's unlikely that someone would apply power in reverse to the Moteino - but it happened to me some time ago. Today I thought that this probably just fried (sorry, Tom, toasted ...) the voltage regulator. So I applied 3V directly at the 3.3V pin. And yes, the moteino came back to life. However it now drew >70mA.

I soldered off the power regulator and the Vin cap - but it's still at 70mA. Should I just forget about this one or do you have other suggestions about how to proceed?

[Felix]

Replace regulator. MCP1703 3.3V

[joelucid]

How could that help if I can't make the Moteino work properly at 3V / 8mhz without the regulator?

[Felix]

Is the bad regulator still soldered?
Did you do *anything* other than hooking up >3.5V on the "VIN" pin? If so that might have damaged it.

[TomWS]

Is the bad regulator still soldered?

I believe he did remove the VR from:

I soldered off the power regulator and the Vin cap - but it's still at 70mA. Should I just forget about this one or do you have other suggestions about how to proceed?

[/quote]
Tom

[joelucid]

No, I removed first the regulator, then the large cap. That didn't change the large current consumption at the 3.3V input. I then removed the flash memory chip I had on the moteino. Afterwards power consumption was a bit lower - but now I can no longer flash the uC using my mkII.

I checked the board using a magnifying glass and thoroughly cleansed it in ethanol, but no change. I'll write this moteino off unless there are other ideas.

This was a new Moteino, I just applied -9V to VIN and the regulator went up in smoke. My hope had been that it had acted as "fuse" protecting the other circuits. Apparently not.

[Felix]

RFM69 boards need a pullup on CS (D10) if you want to reflash them with a MKii or they can garble your programming of the mega.
"3.3" would be the output of the regulator and input to the mega/flash/radio. If you had those devices on the board when the killer voltage was applied, then those might have fried as well and cause the consumption you see.
Otherwise ... I would declare it dead and move on, everything you're describing are symptoms of a damaged moteino.