Awoodda wax soo saarka laysarka ee mashiinnada cusub ee aan la isticmaalin muddo dheer ayaa daciif ah sababahan soo socda:
Awoodda wax-soo-saarka laysarka ee lagu cabbiro warshadda miyay buuxisay shuruudaha farsamada?
Haddii saxnaanta hagaajinta farqiga dhawaaqa uu buuxiyo shuruudaha;
Hubi in uu iftiinku ka soo baxayo diaphragm-yada si buuxda u milicsanaya;
Hubi in luminta galinta dhawaaqa-optical switch uu ku jiro xadka la cayimay.