Write Checks - IBM 1620 Manual

Write Check
Typewriter
r-
ves
- (
C~!:k
)-NO
1) See Memory Trouble-
shooting Information
(Page
4.2)
~-.
No
1) Check Typewriter
Mag. Arm.
2) Check Typewriter Mag.
3) Check Relay Network for
defective Relay Point(s)
Check Bit
Relay Pick
Circuit
No
Yes
Yes
1)
Check
I/o
Exit Trigger
Circuit
2) I Cycle Entry Circuit
3) Check Typewriter to Insure
the Mechanism for Printing
Last Character is operating
properly
Yes
1)
Check Write
Check Trigger
and Circuit
4) Check Letter Cam
~--....Jl)
Check Selector comm}n Contact
#2
(False Check)
~-NO
MDR Correct -vesl
1) Check for correct data
in memory
2) Check MDR Trigger Reset
Circuit
3) Check MBR to MDR Transfer
Servicing Approach:
1) Check MDR lines
to translator
1)
Attempt to establish a failure pattern
2) Load memory with most consistent failure pattern
3) Sync on CR 5 for typewriter translator failures
2) Check Translator VRC Circuit
3) Check Write Check Latch
4) Sync on Trigger 30
I
sync trigger
I
etc.
I
for troubles during set of MDR.
3.4