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4-1
WARNING
_____________
For continued protection against fire, both fuses must be replaced with
fuses of the same type and rating as originally supplied; T, 5A, 250 V.
4-3
CHANGING LINE FUSES
On rare occasions, it may be necessary to change the AC line fuses due to age, overload, etc. There are
two fuses which are located on the top of the power entry module marked with the outline of the fuses.
The fuses can be accessed by prying out the cover of the fuse holder with a small screwdriver after
removing the power cable. The small fuse board can then be slid out of the holder by lifting the black
plastic retainer. Refer to Figure 4-1, Fuse Replacement.
Section IV
TROUBLESHOOTING
4-1
GENERAL
These troubleshooting procedures are provided to aid the operator in identifying failure modes. For fur-
ther troubleshooting assistance or for the replacement of a board or unit, contact Varian Vacuum
Products Service at 1-800-882-7426.
4-2
ERROR CODES
O2 E
Pressure burst caused by a sudden rise in pressure at the ion gauge.
O3 E
No ion current or measurement signal (e.g., bad or missing collector cable connection; bad
electrometer; emission current too low; cold cathode pressure less than minimum pressure
capability – see Specifications page 1-2)
O4 E
Filament overcurrent (shorted filament circuit)
O5 E
Filament undercurrent (open filament); cable not connected, bad control circuit or not
installed correctly
O6 E
Grid voltage low ( grounded grid, bad grid supply)
O7 E
Overtemperature (temperature inside unit over 65°C)
O8 E
Board logic failure (bad component, electrical noise)
O9 E
Overpressure (indicated pressure above high pressure limit of the ion gauge)
12 E
Underpressure (indicated pressure beyond minimum pressure of ion gauge)
13 E
Insufficient current (dirty cold cathode gauge, open cable connection)
14 E
Invalid keypress (locked keypad)