Panasonic UF-5500 Service Manual page 173

7. Check the top cover sensor .......... "TOP COVER OPEN"
Check the voltage at pin W25 of
IC300 (Main Board).
The sensor lever pressed: 0V
(The top cover is closed.)
The sensor lever released: 3.3V
(The top cover is opened.)
8. Check the toner sensor .......... "TONER LOW", "CHANGE DRUM"
Check the waveform at pin AE22 of
IC300 (Main Board).
The waveform should change
between 0V and 3.3V.
(Refer to SENSOR AND SWITCHES
SECTION)
CROSS REFERENCE:
Sensors and Switches Section (P.53)
NG
OK
IC300 NG
NG
OK
IC300 NG
173
Check the connection of signal
line and check the soldering at
R516, R517, Q507 (Main Board).
Check the voltage at pin W25 of
IC300.
NG
Replace SW1 (H.V.P.S)
Check the connection of signal
line and check the soldering at
R523, R527, C516 (Main Board).
Check the waveform at pin AE22
of IC300 again.
NG
Replace IC51 (Toner Board)
UF-5500 / 4500