13. IMAGE FUSING
13.1 FUSING LAMP CONTROL CIRCUIT
The circuit of the main board is different from the A151 and A152 copiers at
the indicated (dashed circle) location.
13.2 OVERHEAT PROTECTION
IC120 and Q101 form an overheat protection circuit. When the fusing lamp is
controlled within the normal range, pin 1 of IC120 stays LOW; therefore,
Q101 stays on, allowing PC402 to operate. If the hot roller temperature
reaches 240
°
C, the resistance of the thermistor becomes too low. At that
time, pin 1 of IC120 becomes HIGH, turning off Q101 and stopping PC402.
At the same time "E53" lights on the operation panel and the power relay
(RA401) turns off.
Even if the thermistor overheat protection fails, a thermoswitch installed in
series with the fusing lamp prevents the fusing unit from excessive
overheating. If the thermoswitch temperature reaches 170°C, the
thermoswitch opens, removing power from the fusing lamp.
T401
A203D510.wmf
IMAGE FUSING
A202/A203
8-20
SM
Summary of Contents for A151
Page 1: ...SERVICE MANUAL PN RCFM3213 A151 A152 A202 A203 RICOH GROUP COMPANIES ...
Page 2: ...SERVICE MANUAL A151 A152 A202 A203 RICOH GROUP COMPANIES ...
Page 3: ...A151 A152 A202 A203 FIELD SERVICE MANUAL PN RCFM3213 ...
Page 4: ......
Page 6: ......
Page 8: ......
Page 10: ......
Page 22: ......
Page 26: ......
Page 27: ...OVERALL MACHINE INFORMATION ...
Page 28: ......
Page 32: ......
Page 33: ...GUIDE TO COMPONENTS ...
Page 34: ......
Page 42: ......
Page 43: ...INSTALLATION ...
Page 44: ......
Page 55: ...SERVICE TABLES ...
Page 56: ......
Page 95: ...REPLACEMENT AND ADJUSTMENT ...
Page 96: ......
Page 193: ...TROUBLESHOOTING ...
Page 194: ......
Page 250: ......
Page 251: ...DOCUMENT FEEDER A296 ...
Page 252: ......
Page 268: ......
Page 274: ......
Page 277: ...A202 A203 SERVICE MANUAL ...
Page 278: ......
Page 337: ...DOCUMENT FEEDER A662 ...
Page 338: ......
Page 359: ...TECHNICAL SERVICE BULLETINS ...
Page 360: ......
Page 372: ...Tech Service Bulletin No 3013 3213 008 Page 2 of 3 Continued ...
Page 373: ...Tech Service Bulletin No 3013 3213 008 Page 3 of 3 ...