Panasonic MC-BJ870-S149, Service Manual

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6.3.3.4. Checking the P.C.B K unit
■ What to check/Method
<Check 1> Checking the insertion, connection and conduction conditions of the connector housing
• Make a visual check of whether the connector housing from the P.C.B A unit is properly inserted and connected.
• Check that there is no burnout or poor connection, etc. of lead wires from the P.C.B A unit by performing a conduction check
using a tester.
<Check 2> Visual check of the P.C.B K unit for any cracking, damaged electrical components, poor soldering,
broken trances, etc.
<Check 3> Method for checking illumination of the “DUST SENSOR” lamp
• Connect a dry battery (3-line series/positive electrode to pin 4) to the P.C.B K unit connector CN800 (between pin 4 and pin 1)
and check that the LED lights up.
*If the “DUST SENSOR” lamp lights up and the results of <Check 1> and <Check 2> are normal, there may be an abnormality in
the P.C.B A unit.
<Check 4> Method for checking illumination of the “CHECK” lamp
• Connect a dry battery (3-line series/positive electrode to pin 4) to the P.C.B K unit connector CN800 (between pin 4 and pin 2)
and check that the LED lights up.
*If the “CHECK” lamp lights up and the results of <Check 1> and <Check 2> are normal, there may be an abnormality in the
P.C.B A unit.
<Check 5> Method for checking illumination of the battery status indicator lamp
• Connect a dry battery (3-line series/positive electrode to pin 4) to the P.C.B K unit connector CN800 (between pin 4 and pin 3)
and check that the LED lights up.
*If the battery status indicator lamp lights up and the results of <Check 1> and <Check 2> are normal, there may be an abnor-
mality in the P.C.B A unit.
■ Action
• Securely connect connector housings.
• Replacing the P.C.B K unit