Thermal Head Voltage Adjustment - Ricoh C231 Service Manual

3.5.7 THERMAL HEAD VOLTAGE ADJUSTMENT

CAUTION
This adjustment is always required when the thermal head or PSU has been
replaced.
Purpose: To maintain master making quality and extend the lifetime of the thermal
head.
Standard: Refer to the voltage value (X) printed on the thermal head. The value
varies from one thermal head to another.
The adjustment voltage should be between X and X - 0.1 V.
Tools: Circuit tester
• Rear cover (
3.2.3)
• Read the voltage value on the decal on the thermal head.
1. Connect the positive terminal of a circuit tester to TP1 and the negative
terminal to TP2 on the PSU.
CAUTION: If the output and ground terminals touch each other, the board will
be damaged.
2. Connect the power plug, and turn on the main switch to access SP mode.
3. Select SP5-12 (Thermal head signal output).
4. Press the # key. Power is continuously supplied to the thermal head, which
could damage the thermal head, so press the clear/stop key if you cannot finish
the adjustment quickly.
A beeper sounds while the power is being supplied.
5. Measure the voltage, and turn RV1 on the PSU until the value is between "+0"
and "-0.1" volts from the value on the thermal head decal.
SM
C267R013.WMF
3-21
MASTER FEED
C267