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Chapter 4 Shuttle Electrical Short Check
Shuttle Electrical Short Check
This procedure checks for metallic debris and checks for hammer coils
shorting to the shuttle frame.
The hammer driver circuit board attached to the shuttle frame assembly can
attract metal objects because of the magnets in the hammer bank. Such stray
metal pieces can cause electrical shorting and damage to the shuttle
assembly. (The hammer driver board does not have a protective cover
because of concerns about component temperatures.)
IMPORTANT
Do this check —
a) If you removed the shuttle cover during servicing and before you re-
install the shuttle cover.
b) Before you replace the controller board.
1. Prepare the printer for maintenance (page 132).
2. Remove the shuttle cover assembly (page 178).
3. Check the shuttle driver circuit board area for any foreign metal parts or
objects (paper clips, staples, screws, chips of metal, broken shuttle spring
fragments, etc.).
4. If you find any foreign metal parts or objects, carefully remove them.
5. Disconnect the hammer bank logic cable (P04) and the hammer bank
power cable (P05) at the shuttle.
6. Set your Ohmmeter to the 10K Ohm scale or the scale closest to 10K
Ohms.
7. Hold the two meter leads apart from each other (not touching anything)
and note how your meter indicates an open circuit. For example, some
meters read OL (Over Load), -1, flashing display, infinite resistance, etc.
8. Attach the common meter lead (usually black) to the shuttle frame.
9. Touch the positive meter lead (usually red) to another part of the shuttle
frame and verify continuity. (Continuity is a low resistance reading of less
than 1 Ohms.)
10. Attach the common meter lead to the shuttle frame, touch the positive
lead to pins 1 through 10 of both hammer bank power plugs J05 and J06
located on the terminator board on the shuttle assembly. Pin 1 of each
plug is the right-most pin as you face the printer. Hold the positive lead for
a few seconds on each pin allowing the meter to stabilize, then read the
resistance:
a. If the resistance of any pin is less
than 1000 Ohms, replace the
shuttle frame assembly (page 215).
b. If pin resistances are 1000 Ohms or greater (including an “open”
reading as in step 7), the shuttle passes the test and is probably okay.
Reconnect hammer bank logic cable (P04) and hammer bank power
cable (P05) to the shuttle
11. Install the shuttle cover assembly (page 178).
12. Return the printer to normal operation (page 133).
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