I tried a different cable, even though I use that cable for other devises, and it now works. But now I get an error in Arduino of:

Arduino: 1.8.0 (Windows 7), Board: "Arduino/Genuino Mega or Mega 2560, ATmega2560 (Mega 2560)"
In file included from sketch\SdFile.h:27:0,
from sketch\cardreader.h:6,
from sketch\Marlin_main.cpp:37:
SdBaseFile.h:38: error: using typedef-name 'fpos_t' after 'struct'
struct fpos_t {
^
In file included from sketch\Marlin.h:10:0,
from sketch\Marlin_main.cpp:30:
c:\program files (x86)\arduino\hardware\tools\avr\avr\include\stdio.h:950:33: note: 'fpos_t' has a previous declaration here
__extension__ typedef long long fpos_t;
^
exit status 1
using typedef-name 'fpos_t' after 'struct'
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