IBM 2104 Model DU3 - Manual (Page 37)

9. Now you must remove the switch card assembly so that you can check and, if
necessary, change the settings of the internal switches. To remove the switch
card assembly:
a. Refer to Figure 15.
b. Unscrew the thumbscrew 1 .
1
Figure 15. Unscrewing the Thumbscrew on the Switch Card Assembly
Installing a 2104 Model DU3 21