IBM 1402 Reference Manual page 59

Customer Engineering Service Panel
The customer engineering service panel (Figures 4-1,
4-2 and 4-3) on the 1402 Card Read-Punch allows the
customer engineer to check certain areas of the ma-
chine without removing covers.
Caution: When the momentary contact display
switches are operated, the commdn hub of the
timer is grounded. Blown fuses and/or machine
damage can result if external leads are connected
when these switches are used.
Dial Display Switch: This toggle switch selects the
timer index to be used with the service panel.
Off Line Card Feed: This rotary switch, when set to
OFF LINE,
allows the feeds to be operated inde-
pendently of the system. The switch must be set to
ON LINE
for the system to operate the 1402.
Read Clutch Trip: This momentary contact switch al-
lows the read clutch to be electrically tripped. The
off line card feed switch must be set on
OFF LINE
to make this switch effective.
Brush Selection: This rotary switch, when set to a
brush position, internally connects brush 3 (outer
light) and 78 (inner light) of the selected set of
brushes to the dynamic timer. When the corres-
ponding feed brush display switch is held on, the
brush timing is displayed on the associated feed
timer index.
For example; to check second read brush timing,
set brush selection to
SECOND READ
and run card
through the read feed with columns 3 and 78
punched. When the read brush display switch is
held
ON,
the brush timing is displayed on the read
feed index.
Read Brush Display: This momentary contact switch
is used with the cam select switch. It displays the
read feed brush timing.
Cam Selection: This rotary switch, when set to a posi-
tion on the dial, selects a certain unit for a timing
check.
Cams and Magnets, CB's and Emit: Only the Model 2
Section 4. Service Aids
is equ.ipped with this switch. This switch and
the cam selection switch allow display of various
cams and magnets, or 8, 4, 2, 1, A, B or C CB's or
emitted 12's or 9's.
Read Cam Display: This momentary contact switch
is used with the cam select switch. It displays the
read feed CB selected for a timing check on the
read feed index.
Voltage Hubs: Each power supply voltage can be
checked at these hubs.
Read Sync: This switch is installed on all Model 3
machines, and on Model 1 machines with the Early
Read Feature. Because the reader clutch has a six-
tooth ratchet, this momentary contact switch is used
to synchronize the read feed and the read index at
31!f (for timing purposes). Functionally, the read
sync switch is part of the customer engineering
service panel; physically, the switch is mounted on a
bracket beside the service panel.
Punch Service Switch Panel
Four switches (Figure 4-1) are used with the dynamic
timer dial on the punch end of the machine. These
switches are mounted near the punch timer dial.
Punch Clutch Trip: This momentary contact switch
allows the punch clutch to be electrically tripped.
The off line card feed switch must be set to
OFF LINE
to make this switch effective.
Sync: Because the punch feed has a four-tooth clutch
ratchet, this momentary contact switch is used
to synchronize the punch feed and the punch index
at 315°.
Punch Brush Display: This momentary contact switch
is used to display the timing of the punch check
brushes when the brush selection switch is set to
the
PUNCH CHECK
position.
Punch Cam Display: This monumentary contact switch
is used with the cam selection switch to display the
punch feed CB selected for a timing check.
4-1