Specifications

4–8 Troubleshooting
Ham. Coil Short *
Instruction Indication Yes No
1. Cycle power: Turn the printer
off. Wait 15 seconds. Turn
the printer on.
“Ham. Coil Short * ” message. Go to step 2. Return the printer
to normal
operation.
2. Turn the printer off. Remove
the ribbon deck. Measure the
coil resistance at hammer
bank connectors J1 – J6:
each coil has a red and a
white wire; put probes where
wire enters the top of the
connector.
Resistance is 4–8 Ohms for all
coils.
Go to step 4. For coils less than
4 Ohms, go to
step 3.
3. If a coil is less than 4 Ohms,
disconnect its hammer bank
connector and measure the
coil resistance again, as in
step 2.
Coil resistance still less than 4
Ohms.
Replace the coil. Go to step 4.
4. Disconnect the hammer bank
cable connectors J1 – J6.
Measure resistance of the
coil leads of the hammer
driver cable. (You are
checking resistance through
both the hammer driver cable
and the hammer driver board.
Do not disconnect the
hammer driver cable at the
hammer driver board. See
Appendix A for pin
assignments.)
Cable resistance is more than
1K Ohm.
For hammers 1 –
40, replace the
hammer driver
board. For
hammers 41 – 88,
replace the
mechanism driver
board.
Replace the
hammer driver
cable.