Weird: Pro Mini sometimes won't start after uploading with an USBasp programmer

Good news first: bootloader burned! :slight_smile:

I was strongly suspecting that the TFT was sucking current in the exact moment when the pro mini is reset. In fact, the default behaviour of the TFT is to show a blank white screen when it is turned on. White color drains a lot of current!

So I completely detached the pro-mini from the breadboard. Then I connected all the wires from the USBasp to the arduino pins.
BOOM!
The "Burn bootloader" command (with Bootloader=No option) has worked like a charm:

/home/giulio/.arduino15/packages/arduino/tools/avrdude/6.3.0-arduino9/bin/avrdude -C/home/giulio/.arduino15/packages/MiniCore/hardware/avr/2.0.0/avrdude.conf -v -patmega328p -cusbasp -Pusb -Uflash:w:/home/giulio/.arduino15/packages/MiniCore/hardware/avr/2.0.0/bootloaders/empty/empty.hex:i -Ulock:w:0x0f:m 

avrdude: Version 6.3, compiled on Jan 17 2017 at 11:00:16
         Copyright (c) 2000-2005 Brian Dean, http://www.bdmicro.com/
         Copyright (c) 2007-2014 Joerg Wunsch

         System wide configuration file is "/home/giulio/.arduino15/packages/MiniCore/hardware/avr/2.0.0/avrdude.conf"
         User configuration file is "/home/giulio/.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: warning: cannot set sck period. please check for usbasp firmware update.
Writing | ################################################## | 100% 0.00s

avrdude: 1 bytes of lock written
avrdude: verifying lock memory against 0x3f:
avrdude: load data lock data from input file 0x3f:
avrdude: input file 0x3f contains 1 bytes
avrdude: reading on-chip lock data:

Reading | ################################################## | 100% 0.00s

avrdude: verifying ...
avrdude: 1 bytes of lock verified
avrdude: reading input file "0xfd"
avrdude: writing efuse (1 bytes):

Writing | ################################################## | 100% 0.01s

avrdude: 1 bytes of efuse written
avrdude: verifying efuse memory against 0xfd:
avrdude: load data efuse data from input file 0xfd:
avrdude: input file 0xfd contains 1 bytes
avrdude: reading on-chip efuse data:

Reading | ################################################## | 100% 0.00s

avrdude: verifying ...
avrdude: 1 bytes of efuse verified
avrdude: reading input file "0xd7"
avrdude: writing hfuse (1 bytes):

Writing | ################################################## | 100% 0.01s

avrdude: 1 bytes of hfuse written
avrdude: verifying hfuse memory against 0xd7:
avrdude: load data hfuse data from input file 0xd7:
avrdude: input file 0xd7 contains 1 bytes
avrdude: reading on-chip hfuse data:

Reading | ################################################## | 100% 0.00s

avrdude: verifying ...
avrdude: 1 bytes of hfuse verified
avrdude: reading input file "0b11110111"
avrdude: writing lfuse (1 bytes):

Writing | ################################################## | 100% 0.01s

avrdude: 1 bytes of lfuse written
avrdude: verifying lfuse memory against 0b11110111:
avrdude: load data lfuse data from input file 0b11110111:
avrdude: input file 0b11110111 contains 1 bytes
avrdude: reading on-chip lfuse data:

Reading | ################################################## | 100% 0.00s

avrdude: verifying ...
avrdude: 1 bytes of lfuse verified

avrdude done.  Thank you.

avrdude: AVR device initialized and ready to accept instructions

Reading | ################################################## | 100% 0.01s

avrdude: Device signature = 0x1e950f (probably m328p)
avrdude: NOTE: "flash" memory has been specified, an erase cycle will be performed
         To disable this feature, specify the -D option.
avrdude: erasing chip
avrdude: auto set sck period (because given equals null)
avrdude: warning: cannot set sck period. please check for usbasp firmware update.
avrdude: reading input file "/home/giulio/.arduino15/packages/MiniCore/hardware/avr/2.0.0/bootloaders/empty/empty.hex"
avrdude: writing flash (2 bytes):

Writing | ################################################## | 100% 0.13s

avrdude: 2 bytes of flash written
avrdude: verifying flash memory against /home/giulio/.arduino15/packages/MiniCore/hardware/avr/2.0.0/bootloaders/empty/empty.hex:
avrdude: load data flash data from input file /home/giulio/.arduino15/packages/MiniCore/hardware/avr/2.0.0/bootloaders/empty/empty.hex:
avrdude: input file /home/giulio/.arduino15/packages/MiniCore/hardware/avr/2.0.0/bootloaders/empty/empty.hex contains 2 bytes
avrdude: reading on-chip flash data:

Reading | ################################################## | 100% 0.07s

avrdude: verifying ...
avrdude: 2 bytes of flash verified
avrdude: reading input file "0x0f"
avrdude: writing lock (1 bytes):

Writing | ################################################## | 100% 0.01s

avrdude: 1 bytes of lock written
avrdude: verifying lock memory against 0x0f:
avrdude: load data lock data from input file 0x0f:
avrdude: input file 0x0f contains 1 bytes
avrdude: reading on-chip lock data:

Reading | ################################################## | 100% 0.00s

avrdude: verifying ...
avrdude: 1 bytes of lock verified

avrdude done.  Thank you.

After that, I uploaded my sketch (32726 bytes) with success by using the command "Upload Using Programmer"

Now the bed news.... :frowning:
After placing the pro-mini back to the breadboard and powering it......... nothing. It doesn't start. The TFT screen stay blank and even pressing the reset button can resuscitate the arduino.

I'm going crazy....