六西格瑪6-sigma培訓實例-資料下載頁
2025-02-21 10:59本頁面
【正文】 ? 答 3:因為潤滑泵失靈了? 答 4:因為潤滑泵的軸磨損了? 答 5:因為雜質(zhì)跑到里面去了5 Why的 分布層次現(xiàn)在 看得到的 ,可 感覺 ,可 測量 問題 緊急處理一次因(近因 )治標對策(暫時 )n次因(遠因 )治本 對策(永久 )真因真因真因真因真因whywhywhywhywhy過去現(xiàn) 象改善行動防呆設(shè)計為什么機器 停了 ?為什么機器會超載 ?問什么軸承會潤滑不 足 ?為什么潤滑泵會失靈 ?問什么潤滑泵的軸會磨損 ?86CCBUSMTQualityIssue（（ WK28）） WHY1216。 Issue Description: BXAMBcan’tpoweronfor5PCSFAIboardsofbuild.216。 WHY 1Whycan’tpoweron?216。 Reason 1+and+5V_MAINjump.216。 Analysis procedure:1. FirstlywecheckthemainpowerforVIN,Standbyvoltage,+and+5Vmainpower.wefound:l TheVINandstandbyvoltagecannormalwork.l +and+5V_MAINisjumping.2. Themainpowerof+and+5V_MAINsupplythepowertokeyponentsofMB(DDR3,PCH,ClockIC,EC,I/O,etc.),thesystemcan’tpoweroniftheyhaveproblem.87216。 WHY 2:Whythe+and+5V_MAINjump.216。 Reason 2: PCHsleepsignal(PCH_SLP_S3_N,PCH_SLP_S4_N,PCH_SLP_S5_N)jump216。 Analysis procedure:1. Checktheschematicandthepowersequenceasbelow,wefoundthesleepsignaljump.andthesleepsignalwasprovidedbyPCH.2. BecauseofthepowersequenceisbasicruleforMBpoweron.SuspectedthisissueshouldbecausedbyPCHsleepsignaljump.CCBUSMTQualityIssue（ WK28） WHY2powersequence88216。 WHY 3:WhythePCHsleepsignaljump216。 Reason 3: V_1P05_MEnovoltage216。 Analysis procedure:1. ChecktherelatedpowerandfoundthevoltageofV_1P05_MEis0V.2. RemoveR617andpullhightheQ87(N溝道 )pinGtodrivertheMOSFETQ2022,butV_1P05_MEstilloutput0V.3. ReplaceonenewQ2022,V_1P05_MEstilloutput0V.4. ShorttheDSofQ2022tosupplythepowerforV_1P05_ME,thenPCHsleepsignalisstableandMBcanpoweronalso.5. Baseonaboveanalysisresult,itcausedbytheV_1P05_MEwithoutvoltage.CCBUSMTQualityIssue（ WK28） WHY3R617V_1P05_MEQ2022GSD89216。 WHY 4:WhytheV_1P05_MEnovoltage216。 Reason 4: MOSFET(Q2022)speccan’tmeettherequirementofdesign216。 Analysis procedure:1. ChecktherelatedcircuitofV_1P05_ME,suspectedtheQ2022MOSFETNG.2. ChecktheBOM,foundQ2026andQ2022usethesameMOSFETwithFDS6679AZ(P/N:BAM66790031).AndchecktheQ2026workfine.3. SwaptheMOSFETbetweenQ2022andQ2026.foundtheQ2022cannormalworkonlocationQ2026.ButQ2026can’tworkonlocationQ2022.4. Baseonabove,excludetheMOSFETrawmaterialNG.5. SuspectedMOSFETapplicationissue,ChecktheMOSFETdatasheetofQ2022andQ87,foundtheVGS(th)(gatethresholdvoltage)ofQ2022is.Q87VDS(on)is~.SotheQ2022drivervoltagejustbaseoncircuitdesign.6. Baseonabove,therootcauseisthatMOSFET(Q2022)speccan’tmeettherequirementofdesign.CCBUSMTQualityIssue（ WK28） WHY4GSD216。 Corrective Action:ShortTermAction:Done1. DeleteQ2022andstuff0ohmresistorbetweenpin1,2andpin7,8ofQ2022.(total40pcs).LongTermActions:1. RDchangedtheMOSFETfromBAM66790031toBAM34150001forbuild.TheVGS(th)ofBAM34150001iswhichisbecanmeettherequirementofdesign.2. Wehavebuilt50PCSBXAMB.Nofoundthisissuehappenedagain.CCBUSMTQualityIssue（ WK28） CorrectiveAction90END
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