Epson TM-U950 Technical Manual page 134

CONFIDENTIAL
Table 4-3. Printer Mechanism Problems (continued)
Problem
Stamp does not
operate.
Different character than
input code is printed.
Characters are not
displayed normally on
the customer display
that is connected to DM
connector of the TM
printer.
Rev. A
Probable Level
Printer is in slip paper B
insertion standby
condition.
Lever-stamp drive is B
worn or damaged.
Solenoid-stamp is worn B
or damaged.
Wire break in solenoid- B
stamp.
Stamp drive signal failure B
Receiver or drive IC (U3) B
failure
Receiver or driver IC (U2) B
failure
TM-U950/U950P Technical Manual
Checkpoint Action
Turn power off and on Remove any pieces of
again and check jammed paper.
whether paper is
released.
Check lever-stamp Replace lever-stamp
drive for wear and drive.
damage
Check solenoid-stamp Replace solenoid-
for wear and damage. stamp.
Check solenoid-stamp Replace solenoid-
coil resistance. (Nominal stamp.
value for 25° C; 19Ω ±
10%)
Check stamp drive Repair drive circuit.
signal.
Check IC (U3) output. Replace IC (U3).
Check if V + terminal Replace IC (U2).
(pin 2) of IC (U2) is +12V.
Check if V - terminal (pin
6) of IC (U2) is -12V.
Troubleshooting 4-21