thanks for your responses!
- i've updated arduino and teensyduino
- I've ringed all contacts from teensy-board to expansion-board (all about 0,3 Ohm) (i will mark them in the picture which ones i used)
- SD-library used: C:\Program Files (x86)\Arduino\hardware\teensy\avr\libraries\SD
i've now checked the example "Cardinfo" (identical with the snipped in first post) and get the same error in console ("initialization failed. Things to check:...")
Code:
Memory Usage on Teensy 4.0:
FLASH: code:45972, data:7080, headers:8384 free for files:1970180
RAM1: variables:9024, code:44264, padding:21272 free for local variables:449728
RAM2: variables:12384 free for malloc/new:511904
Mehrere Bibliotheken wurden für "SD.h" gefunden
Benutzt: C:\Program Files (x86)\Arduino\hardware\teensy\avr\libraries\SD
Nicht benutzt: C:\Program Files (x86)\Arduino\libraries\SD
Bibliothek SD in Version 2.0.0 im Ordner: C:\Program Files (x86)\Arduino\hardware\teensy\avr\libraries\SD wird verwendet
Bibliothek SdFat in Version 2.1.0 im Ordner: C:\Program Files (x86)\Arduino\hardware\teensy\avr\libraries\SdFat wird verwendet
Bibliothek SPI in Version 1.0 im Ordner: C:\Program Files (x86)\Arduino\hardware\teensy\avr\libraries\SPI wird verwendet
and of course you wanted some picures:




any other ideas?
i have also some separate sd-card holders that i could connect (though i would have to look for how to), ideally the built in wourd work somehow