User and Programming Manual - Rev H
California Instruments
May 2000
P Series
36
Red and green LEDs, DS6 and DS7, on the back of the board provide power to DC-AC and the
oscillator board. If either of these are not lit, switch off power, remove large ribbon cable from
DC-DC converter and power up again. If LEDs are lit, the problem is on the DC-AC or the
oscillator board. If the LEDs remain off, replace the DC-DC board.
If LED, DS8, is not lit, no power will be available to run the DC converter drive logic. Replace
DC-DC module.
LED, DS2 (red), indicates 24V fan power available.
LED DS200, will be lit if the DC converter is running. If DS200 is not lit check fuse F1 on the
DC-DC board as in paragraph 7.3.4 above.
If all LEDs are lit and the LED output indicator is lit but no output, then suspect the relay on
DC-AC board.
If all 8 LEDs are lit on the DC-DC converter then the problem is on the DC-AC module. Switch
off, then check wiring from the DC-AC board output to the output sockets on the front panel. If
this is OK check the fuse, F2, on the DC-AC module. Switch off. Remove two screws from
the underside of the enclosure to gain access to the module and F2. If the fuse is blown and a
check shows signs of damage or burning on the board,
DO NOT REPLACE FUSE.
Replace
DC-AC module. If there are no signs of burning or damage on the DC-AC board or
components, then it could be assumed that it is a random fuse failure and it would be OK to
replace the fuse and try again.
WARNING: In most cases when a fuse blows it is caused by a failed power
semiconductor and repeatedly replacing a fuse will only cause severe damage to
that or other assemblies.
