Samsung MultiXpress K7 Series - Electrical Circuit Problem

4.Troubleshooting
4.8.7.Electricalcircuitproblem
NoProblemDescriptionTroubleshootingPage
1SMPSoutputvoltagedroperrorP.4–212
2HDDmakesaloudnoise.P.4–213
3Networkingisnotworking.P.4–213
4UItouchmalfunctionP .4–214
5HomescreeniconisdisappearedorUIscreenisbroken.P .4–216
1)SMPSoutputvoltagedroperror
•Symptom:SomeerrormessagesoccurontheOPE(C3-1312,S3-3121,M1-4111,M1-4211).
•Cause:24Vchannelsoutputvoltagedroptounder21.6Vand5Vchannelsoutputisnormal.
•Troubleshooting
1)Checkall24Voutputchannels(24VS1,24VS2,24VS3,24VS4)whether24Vvoltagecomesoutornot.
2)If24Vvoltagedoesn’tcomeout,check‘24Von/offsignalpin’onthemainboard.
a)Thevoltageat‘24Von/offsignalpin’is0V .→Mainboardandsignalisnormal.
b)Thevoltageatsignalpinis4~5.3V→Mainboardandsignalisabnormal.
3)IfMainboardandsignalisnormalandall24Voutputchannelsarenearly0V ,checkotherparts(i.e.Fuser,motor,
scannerharness,etc.)drivenby24VvoltagebeforereplacingtheSMPS.
4)IfMainboardandsignalisnormalandjustoneortwoorthree24Voutputchannelsarenearly0V ,inspectsome
harnessfromabnormal24VoutputchannelbeforereplacingtheSMPS.
5)IfMainboardandsignalisabnormalandall24Voutputchannelsarenearly0V,inspecttheharness,connectorand
mainboard.
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