IBM 29 Card Punch Field Engineering Maintenance Manual page 9

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Column ColumnjRelease,| Release
Key Mult Skip |Manual|/Manual] Auto |Auto |Auto, |Auto
Function| Punch Punch Key Dup Dup Dup |Dup {Drum |Space
First
Col
1
3 15
4 4-5 3
1 1 1 1 1 1
-2| 5 5-2 5 3=4 3-4
3-4 3 -4 3-4 3-4 3-4 5
5 5 5 5
Second Repeat| 2-5 3-4 Repeat Repeat} 3-4 3-4 Repeat| Repeat
and for All Repeat Repeat} forAll forAIl 5-2 5-2 for All for All
Other Cols for All| for Cols {Cols Repeat |Repeat| Cols Cols
Cols Cycles Field for for
Def Field Field
Def Def
3-4
5
Last
Col
Figure 1-3. Sequence of Operations
Section 2. Diagnostic Techniques
1.3 INITIAL APPROACH
The first step in troubleshooting is to reduce the possible
trouble sources to one of the five operations. Locate the
operation that breaks the correct sequence for the failing
function.
The secondstep is to vary the machine function to one in
which the failing operation occurs in another sequence.
This tests the same operation with a different input. For
example, interposer selection is faulty during keypunching
(2, 34, 5). Varying the function to manual duplication
(5-2, 3-4, 5) allows interposer selection from the pin-sense
input instead of the key input. The cause of the failure, if
in a particular input path,can be discovered in this way. If
the same operation fails, regardless of the input path used,
the failure is commontoall paths.
Enough information may be gained in this way to find
the cause of the failure by using the wiring diagram and the
test probe.
For those troubles that cannot be found by using this
approach, refer to the appropriate section in Chapter 4.
Diagnosis of the complete failure of all machine opera-
tions should be preceded by a continuity check of the
fuses. If attempted punching fails to occur after a card has
been registered at the punch station, the card lever relay
should be checked first. Consistent blowing of fuses
indicates a short or a ground on the machine. Line
terminals and/or cam contacts can be checked, one at a
time, to locate this type of failure. Some common possible
sources of grounds are the starwheel contact and the latch
magnet contact.
1.4 DIAGNOSTIC FLOWCHARTS
Figure 1-4 defines the symbols used in the diagnostic
flowcharts (Figures 1-5 through 1-10). These flowcharts aid
in locating the trouble area when diagnosing fairly consist-
ent failures.
1-2 (4/69)
Trouble approach
action
Error indication
decision
Direction comment)
Figure 1-4. Diagnostic Flowchart Symbols
1.4.1 Start and Run Failures
To locate start and run failures (Figure 1-5), the starwheels
must be raised and blank cards must be used.
1.4.2 Card Transport Failures
Diagnosis of the failure causing incorrect card movement
should include an initial visual check to confirm that the
components of the card transport mechanisms are oper-
ating. When card transport failure occurs, any mark or nick
on the card will help to indicate the source of trouble
(Figure 1-6).
A change in registration during the duplication of one
punched card can be a false indication of card transport
failure. If the escapement moves while the sensing pins are
still up through the holes in the card, the card will be
retarded. The sensing pins usually leave marks on the card.
(See 1.4.4.)
Improperly inserting cards into the pin-sense station can
cause trouble. The card to be duplicated should not be
forced into the pin-sense station before registering the card.
1.4.3 Interposer Selection Failures
Interposer selection may be incorrect from either the
keyboard or pin-sense units, or both. If either unit operates
correctly, the circuits and components of the other unit
must be considered as a source of the trouble. If both units
fail, the trouble is assumed to be in the interposer magnets
and associated circuitry or in the interposer mechanism
(Figure 1-7).
Note that when the interposers have been tripped for any
reason, they must be restored by a drive-unit cycle.
To avoid confusion in diagnosis, the starwheels must be
raised to locate interposer selection failures.
1.4.4 Escapement Failures
Faulty escapement is defined as: escaping too far, not far
enough, notat all, or at the wrong time.
Program control is used with Figure 1-8 to locate
escapement failures. The program card should be punched
for alternate three-column duplications and two-column