IBM 8270, Installation And Service Manual

Page: 53 / 98

Powering on the 8270-800
Step 1. If the 8270-800 has two power supplies, two line cords must be
connected; one for each supply. See Figure 2-16.
Figure 2-16. Powering On the 8270-800
Step 2. Verify that the following LEDs are on (both supplies, if two are installed):
AC OK on the power supply(8270-800 only)
DC OK on the power supply (8270-800 only)
Power (|) on the Token-Ring Processor Card
(See Figure 1-4 on page 1-4 for the location of the LEDs and connectors
on the power supply. See Figure 1-6 on page 1-6 for the location of the
LEDs on the processor card.)
If all of the above LEDs are on, go to “Power-On Checkout” on
page 2-26.
Step 3. If the AC OK LED is not on, there is no ac power being supplied to the
power supply module. Ensure that the line cord is correctly installed. If
that is not the problem, check for power at the ac outlet. If the line cord
is correctly installed and the ac outlet is active, the power supply is
defective and should be replaced.
Step 4. If the AC OK LED is on but the DC OK LED is not on, the power supply
is defective and should be replaced. See “Obtaining Service” on
page 5-6
Step 5. If both power supply LEDs are on but the Power (|) LED on the processor
card is not on, ensure that both the power supply module and the
processor card are correctly seated in the 8270-800 backplane sockets.
If this is not the problem, the power supply fuses protecting the processor
card might be defective and should be checked. See “Obtaining Service”
on page 5-6. If this is not the problem, the processor card is defective
and should be replaced. See “Obtaining Service” on page 5-6
Chapter 2. Installation
2-25