Troubleshooting Nano - dim power LED

I have this Nano that is exhibiting the following behavior:

When I plug it into the computer via USB, the USB port does not register in the computer (MACOS) - no sign of it in /dev.

When I connect it via USBASP and try to upload a sketch, I get this error (I successfully upload sketches to other nanos using USBASP so I know that my adapter and cable work fine):

avrdude: Version 6.3-20171130
         Copyright (c) 2000-2005 Brian Dean, http://www.bdmicro.com/
         Copyright (c) 2007-2014 Joerg Wunsch

         System wide configuration file is "/Applications/Arduino.app/Contents/Java/hardware/tools/avr/etc/avrdude.conf"
         User configuration file is "/Users/michael/.avrduderc"
         User configuration file does not exist or is not a regular file, skipping

         Using Port                    : usb
         Using Programmer              : usbasp
         AVR Part                      : ATmega328P
         Chip Erase delay              : 9000 us
         PAGEL                         : PD7
         BS2                           : PC2
         RESET disposition             : dedicated
         RETRY pulse                   : SCK
         serial program mode           : yes
         parallel program mode         : yes
         Timeout                       : 200
         StabDelay                     : 100
         CmdexeDelay                   : 25
         SyncLoops                     : 32
         ByteDelay                     : 0
         PollIndex                     : 3
         PollValue                     : 0x53
         Memory Detail                 :

                                  Block Poll               Page                       Polled
           Memory Type Mode Delay Size  Indx Paged  Size   Size #Pages MinW  MaxW   ReadBack
           ----------- ---- ----- ----- ---- ------ ------ ---- ------ ----- ----- ---------
           eeprom        65    20     4    0 no       1024    4      0  3600  3600 0xff 0xff
           flash         65     6   128    0 yes     32768  128    256  4500  4500 0xff 0xff
           lfuse          0     0     0    0 no          1    0      0  4500  4500 0x00 0x00
           hfuse          0     0     0    0 no          1    0      0  4500  4500 0x00 0x00
           efuse          0     0     0    0 no          1    0      0  4500  4500 0x00 0x00
           lock           0     0     0    0 no          1    0      0  4500  4500 0x00 0x00
           calibration    0     0     0    0 no          1    0      0     0     0 0x00 0x00
           signature      0     0     0    0 no          3    0      0     0     0 0x00 0x00

         Programmer Type : usbasp
         Description     : USBasp, http://www.fischl.de/usbasp/

avrdude: auto set sck period (because given equals null)
avrdude: error: program enable: target doesn't answer. 1 
avrdude: initialization failed, rc=-1
         Double check connections and try again, or use -F to override
         this check.


avrdude done.  Thank you.

the selected serial port 
 does not exist or your board is not connected

And in both cases, the power LED lights up … but it’s so dim, I almost have to cup it with my hands to see it. I’ve tried tagging all the solder points on the bottom side of the board but the behavior is still the same.

Anyone have any idea which components could fail that could possibly cause this behavior?

Thank you

That's a strange symptom. Does the LED on the USBAsp get dimmer when you connect it to the nano you're trying to program?

If so, that would point to a near-short on the board (most likely the regulator, but most ICs, if sufficiently abused, will fail to near-short) - or it could have conductive debris on the board, or something like that.
If not, the problem is strange indeed, and I don't have a ready explanation for it.

In any event, nano clones are like $2-3 on ebay. It's not really worth fixing a failed nano, especially because when something horrible enough to trash one chip like that occurs, it usually damages other parts on the board as well

DrAzzy:
In any event, nano clones are like $2-3 on ebay. It's not really worth fixing a failed nano, especially because when something horrible enough to trash one chip like that occurs, it usually damages other parts on the board as well

Yeah ... It just seems to be the norm with the Nano clones, that the USB craps out on them sooner rather than later, If I had any confidence that a NON-clone would be more reliable, I'd buy a few ... but I have no experience with the originals and to me ... parts is parts ... if USB is the weak link in the Nano design, and the design is no different between an original and a clone ... why should I think that spending more on an original would cause me less headache?

And NO, the USBASP programmer does not go dim when plugged into this Nano ... I would definitely have noticed that and started looking for the short ...

I think I'll just keep saving these failed nanos and the next time I go to a lake, I'll see how well they skip across the top of the water :wink: