Fuse Removal And Inspection - Hach Sigma 950 Instrument Manual

Figure 20 CPU Board
J11
ID
F1 RS485 Interface Connector
ID Description
J1 Liquid Crystal Display (LCD) Board
J2 Mechanical Totalizer
J3 not used
J4 Base Board
J5 Memory Backup Battery Pack
J6 RS232 Serial Port
J7 RS-485 - Submerged Pressure Probe - (not used on bubbler 950)
J8 Modem Option Module
J9 Liquid Crystal Display (LED back-light)
J10 Keypad
J11 not used

9.4.1 Fuse Removal and Inspection

J6
J10
Table 32 CPU Board Fuse
Description
Table 33 CPU Board Connectors
To remove a fuse, pull it straight out of the clips that hold it in place. Usually a close look
will tell you if a fuse is blown. The wire strand inside the glass tube will be broken.
Occasionally it may take an ohmmeter to verify if a fuse is good or not. You may need to
remove plug J1 to access fuse F1.
Always replace any fuse with the exact same size and type rating. Over-rating or
bypassing a fuse could lead to severely damaged equipment.
J9
J4
J5
J2
2 Amp, 250 V ac Fast-blow, 5 x 20 mm (P/N 2605)
Maintenance
J7
J1
F1
J8
Type & Rating
77