Write Checks - IBM 1620 Manual

Write Check
Yes
1) See Memory
Trouble-shooting
Information
r
NO-fR
correc)
1) Check for correct
data in memory
2) Check MDR Trigger
Reset Circuit
3) Check MBR to MDR
Transfer
Servicing Approach:
1624
Yes
Yes~
1) Check MDR lines
to translator
2) Check extension to
1624
3) Check PCB-2
4) Check Mag. Coi I for
position fail ing
5) Check for defective
diode across failing
punch Mag.
1) Attempt to establ ish a fai lure pattern.
2) Load memory with most consistent failure pattern.
3) Sync on most convenient PCB Integrator for
translator problem.
4) Sync on Trigger 30, sync trigger, etc., for
troubles during set of MDR.
3. 15
Yes
1) Check
I/o
Exit
Trigger Circuit
2) I Cycle Entry Circuit
3) Check 1624 to Insure
the mechanism for
punch ing last charac,ter
is operating properly
1) Check Ball Check Contacts
2) Check PCB-3 Integrator
3) Check Write Check Latch
1) Check Write
Check Trigger
and Circuit