HP LaserJet II Serie Manual De Instrucciones página 214

HP 33440/HP 33449 COMBINED SERVICE MANUAL
Thermistor Functional Check
Under normal operating conditions, Thermistor resistance decreases as ik operating temperature
increases. Because of this characteristic it is diffictit to measure an accurate resistance value for
the Thermistor. However, some conclusions may be made concerning the condition of the printer
Thermistor with a resistance check. Me&surethe Thermistor value using the following Electrical
Check.
1. Power off the printer.
2. Remove the protective cover from the Iefi side of the Fusing Assembly to access the Exit Sensor
PCA.
3. Measure the Thermistor's resistance at J332, pins 1 and 2 (see Figure 7-21). At ambient room
temperature (72° F, 23° C), the resistance should be approximately 1,130 kohms. If the printer
has been operating for some time, the resistance value will be much lower. If the Thermistor
appears to be either open or shorted, replace the Thermistor@tit Sensor PCA.
00
s
12 Oo
,Qo . .
00
J3J2.
m
o
00
0
0 0
0 0
0
000
0
0
0
OOOOOOO. O
0
0
0
Exit Sensor PCA
i
Uuuuuuu
Figure 7-21. Thermistor Resistance at
J332
7-50