Toshiba Strata DK 280 Installation Manual page 649

2. Verify the power supply ON/OFF switch is in the
ON position.
Note:
The base cabinet ON/OFF switch must be ON
to allow expansion cabinet power supplies to
operate.
Verify that the data ribbon cable is plugged into
the base from all expansion cabinets.
3. Ensure the AC power cord is plugged into the
RPSU280 AC IN connector and the commercial
AC outlet (or power strip (RPSB) if used). The
green POWER LED indicator will be on when AC
power is connected to the RPSU280 and the
power supply ON/OFF switch is ON. Take
appropriate action to restore AC power if
necessary.
Note:
The green power LED indicates that AC
voltage is present at the AC IN connector only
when the RPSU280 ON/OFF switch ON. This
is helpful for battery backup systems-the
POWER indicator will be OFF and the +5V
and -5V indicators will be ON when the
DK280 is operating on reserve power
(batteries).
4. Verify that the +5V and -5V green LED indicators
are ON. If one or both indicators are OFF, remove
cabinet PCBs one at a time and check if +5V or
-5V indicators turn on (it may be necessary to turn
power OFF and ON to restore &5 volts). Replace
defective PCBs causing &5 volt fault.
IMPORTANT!
If a CRCU PCB is installed on an RCTU PCB,
25 volts will turn off. Do not install CRCU on
RCTU. Only RRCS DTMF PCBs can be
installed on RCTU.
5. Lightly press the three -24V circuit breakers to
ensure they have not accidentally opened during
shipment. If a circuit breaker continues to "trip,"
remove cabinet PCBs, one at a time, and try to
reset the circuit breaker. Replace defective PCBs
if causing -24 volt fault. See the 24V circuit
breaker assignments in Figure 12-2 below. If
breakers continue to trip, go to Step 7.
6. Using a DC voltmeter, measure the power supply
DC output voltages at the "DC OUT" connector on
the RPSU280. Refer to Figure 12-2 for voltage pin
7.
8.
locations and specifications. Place the positive
(black) meter lead on the FG screw. Insert the
negative (red) meter lead tip into the DC out
connector until it makes contact.
Make sure that +5 volt, -5 volts, and -24 volts are
within the range specified in Figure 12-2. Do this
test with PCBs inserted; if a voltage(s) is not within
specification, remove PCBs, one at a time and
recheck the voltage. (Power may have to be
turned OFF and ON to restore a voltage.) Replace
any PCB which causes a voltage fault. If voltage
tests out of specification with all PCBs removed
from the cabinet, go to Step 7.
Unplug the cabinet DC power connector from the
RPSU280 "DC OUT" jack. Attempt to reset -24
volt breakers per Step 5. If breaker cannot be
reset replace power supply; if breakers reset go to
Step 8.
Check the power supply DC voltages measuring
at the DK280 "DC OUT" jack with the black meter
lead on the BATT "+" terminal. If the DC voltages
are within specification when the cabinet DC
power connector is disconnected but not within
specification when the cabinet is connected, the
cabinet is probably defective.
If the DC voltages are not within specification
when the cabinet DC power connector is
unplugged, the RPSU280 power supply probably
is defective. Replace the defective cabinet or
RPSU280 power supply per Chapter 3-Cabinet
Installation.
I
+5 Volts (white wire) cannot be checked with
IMPORTANT!
the DC out cable disconnected.
9. Using the DC voltmeter, check the RPSU280
battery charger as follows: Remove the battery
cable from the power supply "BATT" connector.
Place the positive (black) meter lead on the "+"
BATT pin and the negative (red) meter lead on the
'I-" BATT pin. The allowed range is (-26.3 volts -
-27.8 volts). If BATT output is not within
specification, replace the RPSU280.
January 1996
12-3