Disassembly of DP-9900Plus/DP-9900 
3-11 
 
3.6.  Disassembly of I/O Board 
1.  Perform the procedures described from section 3.5.1 to section 3.5.6. 
2.  Release the six M4×8 screws that secure the upper rear cover. Disconnect cables 
from the I/O board and then remove the upper rear cover with the I/O board on it. 
 
3.  Release the six screws that secure the I/O board to the upper rear cover.