user71623: I have two sunfounder mega2560s. I am using one as an ISP programmer and the other is my target. The programmer has the original bootloader on it. I have placed the ArduinoISP sketch on my programmer and connected LEDs and stuff as here: https://www.arduino.cc/en/pmwiki.php?n=Tutorial/ArduinoISP
I have connected all six pins on my programmer to all six pins on the target. I'm using the ICSP towards the middle of the board on both boards as opposed to the one near the USB cable.
I am trying to place megacore on the target. I have followed the directions here: https://github.com/MCUdude/MegaCore#how-to-install.
I am running Arduino IDE on Windows 10. I am selecting Tools->Board->megacore->Mega2560 and then Tools->Programmer->Arduino as ISP.
I believe all of this setup is correct, so I Click Burn Bootloader. I get the following results:
Arduino: 1.8.15 (Windows Store 1.8.49.0) (Windows 10), Board: "ATmega2560, Yes (UART0), EEPROM retained, Arduino MEGA pinout, BOD 2.7V, LTO disabled, External 16 MHz"



avrdude: Version 6.3-20201216

         Copyright (c) 2000-2005 Brian Dean, http://www.bdmicro.com/

         Copyright (c) 2007-2014 Joerg Wunsch



         System wide configuration file is "C:\Users\ThomH\Documents\ArduinoData\packages\MegaCore\hardware\avr\2.1.3/avrdude.conf"



         Using Port                    : COM19

         Using Programmer              : stk500v1

         Overriding Baud Rate          : 19200

         AVR Part                      : ATmega2560

         Chip Erase delay              : 9000 us

         PAGEL                         : PD7

         BS2                           : PA0

         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    10     8    0 no       4096    8      0  9000  9000 0x00 0x00

           flash         65    10   256    0 yes    262144  256   1024  4500  4500 0x00 0x00

           lfuse          0     0     0    0 no          1    0      0  9000  9000 0x00 0x00

           hfuse          0     0     0    0 no          1    0      0  9000  9000 0x00 0x00

           efuse          0     0     0    0 no          1    0      0  9000  9000 0x00 0x00

           lock           0     0     0    0 no          1    0      0  9000  9000 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 : STK500

         Description     : Atmel STK500 Version 1.x firmware

         Hardware Version: 2

         Firmware Version: 1.18

         Topcard         : Unknown

         Vtarget         : 0.0 V

         Varef           : 0.0 V

         Oscillator      : Off

         SCK period      : 0.1 us



avrdude: AVR device initialized and ready to accept instructions



Reading | ################################################## | 100% 0.02s



avrdude: Device signature = 0x000000 (retrying)



Reading | ################################################## | 100% 0.02s



avrdude: Device signature = 0x000000 (retrying)



Error while burning bootloader.

Reading | ################################################## | 100% 0.02s



avrdude: Device signature = 0x000000

avrdude: Yikes!  Invalid device signature.

         Double check connections and try again, or use -F to override

         this check.





avrdude done.  Thank you.

I have double checked all of my connections and am powering the target 2560 from a power block on a USB cable.
All research on the web turned up only issues with connections or separate power. Also, I don't know how to use the avrdude from the command prompt to add the -F as suggested.
Having tried everything, I'm looking for help here. Thanks.

user71623: The answer was that you must connect the reset pin of the target ICSP to pin 10 of the programmer Mega 2560. This was not very clear in the tutorial here: https://www.arduino.cc/en/pmwiki.php?n=Tutorial/ArduinoISP.
This fixed the problem for me, so it was a connection issue.

71623: <p>I have two sunfounder mega2560s. I am using one as an ISP programmer and the other is my target. The programmer has the original bootloader on it. I have placed the ArduinoISP sketch on my programmer and connected LEDs and stuff as here: <a href="https://www.arduino.cc/en/pmwiki.php?n=Tutorial/ArduinoISP" rel="nofollow noreferrer">https://www.arduino.cc/en/pmwiki.php?n=Tutorial/ArduinoISP</a></p>
<p>I have connected all six pins on my programmer to all six pins on the target. I'm using the ICSP towards the middle of the board on both boards as opposed to the one near the USB cable.</p>
<p>I am trying to place megacore on the target. I have followed the directions here: <a href="https://github.com/MCUdude/MegaCore#how-to-install" rel="nofollow noreferrer">https://github.com/MCUdude/MegaCore#how-to-install</a>.</p>
<p>I am running Arduino IDE on Windows 10. I am selecting Tools-&gt;Board-&gt;megacore-&gt;Mega2560 and then Tools-&gt;Programmer-&gt;Arduino as ISP.</p>
<p>I believe all of this setup is correct, so I Click Burn Bootloader. I get the following results:</p>
<pre><code>Arduino: 1.8.15 (Windows Store 1.8.49.0) (Windows 10), Board: &quot;ATmega2560, Yes (UART0), EEPROM retained, Arduino MEGA pinout, BOD 2.7V, LTO disabled, External 16 MHz&quot;



avrdude: Version 6.3-20201216

         Copyright (c) 2000-2005 Brian Dean, http://www.bdmicro.com/

         Copyright (c) 2007-2014 Joerg Wunsch



         System wide configuration file is &quot;C:\Users\ThomH\Documents\ArduinoData\packages\MegaCore\hardware\avr\2.1.3/avrdude.conf&quot;



         Using Port                    : COM19

         Using Programmer              : stk500v1

         Overriding Baud Rate          : 19200

         AVR Part                      : ATmega2560

         Chip Erase delay              : 9000 us

         PAGEL                         : PD7

         BS2                           : PA0

         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    10     8    0 no       4096    8      0  9000  9000 0x00 0x00

           flash         65    10   256    0 yes    262144  256   1024  4500  4500 0x00 0x00

           lfuse          0     0     0    0 no          1    0      0  9000  9000 0x00 0x00

           hfuse          0     0     0    0 no          1    0      0  9000  9000 0x00 0x00

           efuse          0     0     0    0 no          1    0      0  9000  9000 0x00 0x00

           lock           0     0     0    0 no          1    0      0  9000  9000 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 : STK500

         Description     : Atmel STK500 Version 1.x firmware

         Hardware Version: 2

         Firmware Version: 1.18

         Topcard         : Unknown

         Vtarget         : 0.0 V

         Varef           : 0.0 V

         Oscillator      : Off

         SCK period      : 0.1 us



avrdude: AVR device initialized and ready to accept instructions



Reading | ################################################## | 100% 0.02s



avrdude: Device signature = 0x000000 (retrying)



Reading | ################################################## | 100% 0.02s



avrdude: Device signature = 0x000000 (retrying)



Error while burning bootloader.

Reading | ################################################## | 100% 0.02s



avrdude: Device signature = 0x000000

avrdude: Yikes!  Invalid device signature.

         Double check connections and try again, or use -F to override

         this check.





avrdude done.  Thank you.
</code></pre>
<p>I have double checked all of my connections and am powering the target 2560 from a power block on a USB cable.</p>
<p>All research on the web turned up only issues with connections or separate power. Also, I don't know how to use the avrdude from the command prompt to add the <code>-F</code> as suggested.</p>
<p>Having tried everything, I'm looking for help here. Thanks.</p>
 71623: <p>The answer was that you must connect the reset pin of the target ICSP to pin 10 of the programmer Mega 2560. This was not very clear in the tutorial here: <a href="https://www.arduino.cc/en/pmwiki.php?n=Tutorial/ArduinoISP" rel="nofollow noreferrer">https://www.arduino.cc/en/pmwiki.php?n=Tutorial/ArduinoISP</a>.</p>
<p>This fixed the problem for me, so it was a connection issue.</p>
