For block, the national institute of korean language(https://www.korean.go.kr/front/onlineQna/onlineQnaView.do?mn_id=216&qna_seq=81761) specifies that the correct translation is 블록, not 블럭. Both translations, despite 블럭 being the wrong translation, are being used. All 블럭 have been changed to 블록.
설계도 and 회로도 are both schematic.