Skip to main content

Timeline for Arduino nano stopped working

Current License: CC BY-SA 3.0

7 events
when toggle format what by license comment
Jul 23, 2015 at 3:22 comment added Nick Gammon If it comes to the high-voltage programming I would cut the trace to the resistor. That would be safest. In any case the chip has an internal pull-up. You would have the issue of the reset button not working afterwards, though. The suggestion by @IgorStoppa about the male header is probably a good compromise.
Jul 22, 2015 at 20:55 comment added Nick Gammon Yes, that might work. I think I like the idea of the 2.5 k resistor in case the processor uses less power at some point. Indeed, the fluctuations in power during programming mode (if there are any) might be amplified by this 12 V effect. You also would need to solder onto XTAL1 which is not broken out to a pin. Again, though, I would try ICSP programming first. Much simpler to do, and there is no real proof at this stage that whatever-it-is that is wrong could be fixed by high-voltage programming but not ICSP programming.
Jul 22, 2015 at 8:30 comment added Gerben @NickGammon the 12v is going through a 1k resistor. The 5v would rise by no more than a volt. Now for the math (correct me if I'm wrong); The 328 uses at least 5mA (5v @8Mhz), which is equivalent to a 1k resistor (R=V/I). So together with the 1k on the reset line, it would create a voltage divider, giving 6v at the VCC point. 6v is just with the maximum ratings. If there is anything else in the circuit using current, it would be even lower than 6v. Or just add a 2.5k resistor between vcc and gnd to get exactly 5v. Pretty interesting point you made. Quite a brain-breaker to figure out.
Jul 22, 2015 at 6:39 comment added Nick Gammon If was desperate, I would consider doing that. The other thing is that you have a whole lot of wires to connect (as the chip is soldered in). I've got a post about high-voltage programming which shows that you have around 20 wires to connect. I'd be a little surprised if it came to that. Either the chip has been hopelessly damaged, or you can recover with ICSP programming.
Jul 22, 2015 at 6:05 comment added Igor Stoppa @NickGammon: I wonder if there is any relatively simple way to cut a track or two and place jumpers on them. A bit like the procedure to make USB-reset optional for the UNO when enabling debugWire. First thing that comes to my mind is to desolder the pullup, use the pads to wire/solder a male pin header and attach the resistor to a female pin header.
Jul 22, 2015 at 0:01 comment added Nick Gammon It's not really practical with a chip soldered to the board to do high-voltage programming, because you would send 12 V via the /RESET pull-up resistor to the +5 V pins, which would damage the chip.
Jul 21, 2015 at 23:23 history answered Igor Stoppa CC BY-SA 3.0