Bio-Rad CHEF Mapper® XA System - Manual (Page 60)

Section 10
Maintenance of Equipment
10.1 Replacing Electrodes
Rinse the gel chamber after every run. Remove dirt and buildup with laboratory detergent
and a fine cloth. Do not to touch the electrodes.
If an electrode breaks or leaks at the O-ring, it may be replaced. Additional electrodes
are available from Bio-Rad Laboratories (see Section 13).
To replace an electrode:
1. Turn the gel chamber upside down, and remove the six screws.
2. Lift off the base plate.
3. Remove the hexagonal nut on the wire, remove the nut on the electrode to be replaced, and
push down firmly on the post to remove the old electrode.
4. Turn the box over, insert the new electrode, pack with self-leveling silicone sealant (avail-
able at most hardware stores), and replace the nut.
5. Replace the wire and base plate.
If one of the pins to the serial cable bends, use tweezers to carefully straighten it.
Replacement cables may be ordered from Bio-Rad.
10.2 Fuses
If the DC voltage to the electrodes exceeds 300 V, the 0.5 ampere FB fuse may blow.
The high-voltage indicator light on the power module will go off. Replace the fuse by unscrew-
ing the cartridge at the front of the power module. Replace with 0.5 ampere FB (fast blow)
fuse. Make sure the power module is off when replacing a fuse.
If there is a power surge, the SB fuses may blow. The AC light on the power module will
go off. The fuses are at the rear of the power module, mounted inside the power entry mod-
ule. Replace the fuses with 3.0 A SB if your local voltage is 120 V or 100 V, or with a 1.5 A
SB if 220 V or 240 V.
If the unit still does not operate, contact Bio-Rad Laboratories. Do not attempt to open and
repair the power module, or the warranty may be voided.
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