Summary: At power up, the printer display shows Fault: SMHI noresp or Fault:SMHI error. While printing, the display shows Fault: Shuttle (Fault: Image Logic is caused by the Fault: Shuttle).

Cause: The printer shuttle mechanism is not shuttling or shuttling at an improper frequency.

User Level Troubleshooting:

Paper Jam
If the printer display showed Fault: Shuttle before turning the power off, there may be a paper jam. Open print gap adjust knob to the load position and remove all paper. Turn on the printer power. If the printer powers up to Striker Bar Open and Papaer Out, visually check throat area for a paper jam. If labels were printed, check for stuck labels. Correct any paper jams, reset the print gap adjust to normal setting, and re-load the paper.

Print Modules and Ribbon Shield
Loose or missing print modules will affect the shuttle balance, as will a damaged or missing ribbon shield.

Shipping Hardware
Verify all shipping screws and blocks have been removed. Shipping hardware should have been removed when the printer was installed. If the shipping bolts were removed, but the blocks were left in the printer, the printer may run properly for some time. If the shipping blocks shift, they may jam the shuttle.

Verify all shipping screws and blocks have been removed. There are a total of five 8mm bolts, all painted yellow. Two bolts are located on the shuttle bar, one far left and one far right. The remaining three are inside the main cabinet. Two are mounted through black blocks inside rear behind the lower tractor assembly, and one is mounted through a block in the middle front.

Technician Level Troubleshooting

This section presumes a technical knowledge of the printer, and that the service manual is at hand.

Shuttle Bar
If the shuttle bar has been disassembled or modified in any manner, it must be replaced. The shuttle bar is a precision maufactured item and any modifications will cause a loss of mechanical resonance. This includes tapping out the air duct mounting screw to accomadate a larger screw.

Power Supply
Non XT models: Remove left side door panel and inspect that all green LED's are lit. This verifies all power supply voltages are present. If any LED's are not lit then replace that PWB card.

XT models: Remove the back panel and check the green LED (all voltages normal) on the SPSC board. If not lit, replace the SSPS. If the red LED is lit (overvoltage on 42V bus) replace the SSPS.

Shuttle Drive Test
Remove all the logic boards from the card cage in the right side of the printer. On the SMHI board, move the jumper on J2 to the upper position. Re-install the SMHI board only. Turn on the printer power. The printer shuttle should swing constantly.

If the shuttle does not swing, the problem is in the SMHI, the shuttle motor, the LVT coil, or the cabling. If the shuttle does swing, the problem is probably in the SMHI.

SMHI Board
Check 5A fuse F3- this provides +42 volts to the Shuttle Motor drive circuit. If the paper motion detector option is not installed, F2 may be considered a spare fuse (F1 is for the paper and ribbon motors, on SMHI/5 and below it is 3A, on SMHI/6 and above it is 5A). If F3 repeatedly blows, check the shuttle motor resistance (below). If the motor is not shorted, replace the SMHI board

VCOI Adjustment
Connect a scope or meter to the VCOI test point on the SMHI board. AC voltage will be present on this test point. Adjust the phase pot on the SMHI board until the AC voltage is as close to 0 volts as possible with the shuttle drive running (refer to the shuttle drive test above).

Shuttle Motor
If the shuttle motor was replaced, ensure the weights were transferred from the old motor to the new motor.

Motor resistance should read 6.6 ohms ± 10% measured at P3 or at the SMBP P1 pins 11 and 13 with the SMHI removed. SMBP P1 pins 11 and 13 should measure open to chassis ground.

LVT Coil. Coil resistance should read 240 ohms ± 10% measured at P7 or at the SMBP P1 pins 31 and 33 with the SMHI removed. SMBP P1 pins 31 and 33 should measure open to chassis ground.