IBM 5500-01E, Operational, Installation, And Maintenance Manual

Page: 101 / 192

101
Determining Your Problem Category
Decide the category of your problem (A, B, C, or D) and follow the
instructions in the order shown in the category column.
A - New or changed installation with a solid problem.
B - New or changed installation with an intermittent problem.
C - Unchanged installation with a solid problem.
D - Unchanged installation with an intermittent problem.
Adding the 5500 Control Unit to Existing Twinax Cable Runs
When upgrading from an older twinax workstation controller to a newer
workstation controller (such as the IBM 5500 Control Unit), the performance
Figure 38: Problem Category Procedures
Categories
Description of Check Task
A B C D
2 2 1 1
Ensure that terminals have no internal hardware failures or known
problems.
4 5
Check for a valid twinax installation cable length, routing, number of
connections.
3 3 3 3
Check cables for opens and shorts. Refer to “Step-by-Step Cable
Debugging” on page 105.
6 9 9
Check for Ground Potential Difference problems. Refer to “Step-by-
Step Cable Debugging” on page 105.
4
Check all cables for correct phase connections. Refer to “Step-by-Step
Cable Debugging” on page 105.
5 6
Check for the presence of AC noise. Refer to “Step-by-Step Cable
Debugging” on page 105.
6 8
Use TDR to analyze signal quality. Refer to “Advanced Time Domain
Relfectometry (TDR) Procedure” on page 113.
5 7 4 4
Ensure the 5500 twinax controller card is functioning correctly and
within specifications.
1 1 2 2
Visually check the entire twinax run for good wire connections. Refer
to“Step-by-Step Cable Debugging” on page 105.
8 7
Perform a ground loop impedance test on all the terminals. Disconnect
the twinax cabling for this test. Refer to “Step-by-Step Cable
Debugging” on page 105.