Jumper Positions - IBM 3279 2A Maintenance Information

3276
Repair Action
Error Code Explanation
Code (3279 logic card)
41 Keyboard logic, then
Invalid scan code received
cable, then 02.
42 Keyboard logic, then 02. Keyboard overrun
43 G2 (MRC), then 02.
MRC data parity error
44 G4 (selector pen), then
Selector pen data parity error
02, then C2.
45 G2 (MRC), then 02. No response from MRC
55 82 then 02, then C2. Storage parity error
56 82 then 02, then C2. Storage parity error
60
G2 (MRC), then 02.
MRC timeout
61
G4 (selector pen), then
Selector pen timeout
02, then C2.
70
C2, then coaxial cable, then 02. No response from terminal (timeout)
71 C2, then coaxial then 02. Adapter receive parity error
72 C2, then 02. Data parity error
73·
02. Lost Operation Complete this display
74
02, then features. Feature timeout
77 02, then C2. Device check (buffer parity)
78
02, then C2. POR signal error
• Do the control unit and its features support the 3279 features?
Check ECS card switches, and keyboard jumpers (see Figure 6-14).
Note:
For other error codes, see control unit or installed RPQ documentation.
Figure 2-9. Error Codes From IBM 3276 Control Unit
1.7
Jumper
Positions
A number of jumper positions are available to aid
d!splay adjustments and fault-finding.
3279 MIM
Chapter 2. Maintenance Aids 2-13