ABB DCS AC700F CPU模块：CD722F AX721F
ABB DCS AC700F CPU模块：CD722F AX721F
ABB DCS AC700F CPU模块：CD722F AX721F
一台变频器，开关电源出现间歇振荡现象，操作显示面板也时亮时熄。此为开关电源负载过重或存在短路状态的典型故障，负载异常引发了开关电源电流检测电路的保护动作，使开关电源处于间歇振荡状态。
用逐路脱开负载电路的方法，排查短路故障是出在哪路负载电路，或停电后，测各路供电电源的输出端，是否有阻值变小或短路现象。测量+5V电源两端，呈现7.8Ω的小电阻值，而正常的电路阻值约为数百Ω。判断+5V负载电路有短路现象，将+5V负载电路脱开后，开关电源有了稳定输出，说明故障就在+5V负载电路。
+5V供电电源由排线端子去了CPU主板，供CPU芯片及外围电路，电路范围比较广，CPU主板上+5V供电的集成电路比较多，达二十几片，用常规排除法检查短路故障的，须将各片IC电路的+5V供电脚挑开，配合电源输出端电阻值的检测，当挑开某片IC供电脚，电源输出端7.8Ω的小阻值变为正常的电阻值后，说明该片IC即存在短路故障，当然测量挑开IC的供电脚，检测其供电引脚的电阻值也是一样。
无法预测需要挑开多少片IC后，才能找到故障IC。CPU主板元件焊接的“精致程度”已艰接近于手机的线路板，IC电路全为贴片元件，将IC引脚的铜箔条说成比头发丝还细，甚至于都不算是夸张。手底一不小心，挑掉铜箔条的话，想接起来都比较困难，挨片挑，这个法子也太笨了。
由于变频器的开关电源本身负载能力有限，接于故障电路时会引发过流保护，使开关电源停止输出。故采用外接容量较大的+5V电源，串接5Ω5W限流电阻接到CPU主板上，通电几分钟后，用手触摸CPU主板上的IC芯片，哪片烫手，有异常温升，即是哪片IC已经坏掉了。
这个法还真灵，挑开两片有异常温升的IC供电引脚，测其引脚电阻，均在十几Ω左右。此时再测+5V电源输出端，已经是数百Ω的正常阻值了。
这是个好法子，算是将错就错或将计就计或顺势而为，利用外接+5V供电，既对好的IC没什么危害，又使坏IC持续升温，暴露在我手指的“测温仪”下。特别适宜于检测CPU主板上出现的IC短路故障。
P0922SZ
P0922TC
P0922TE
P0922TH
P0922TL
P0922TV
P0922UA
P0922UD
P0922UG
P0922UJ
P0922UK
P0922UL
P0922UM
P0922UN
P0922UP
P0922UQ
P0922UR
P0922US
P0922UT
P0922UU
P0922UV
P0922UW
P0922UX
P0922VC
P0922VS
P0922VT
P0922VU
P0922VV
P0922VW
P0922WE
P0922WF
P0922WK
P0922WN
P0922WP
P0922WQ
P0922WR
P0922WS
P0922WT
P0922WU
P0922WW
P0922WZ
P0922XQ
P0922XR
P0922XS
P0922XT
P0922XU
P0922XV
P0922XW
P0922XX
P0922XY
P0922YA
P0922YC
P0922YH
P0922YJ
P0922YK
P0922YU
P0922ZA
P0922ZB
P0922ZC
P0922ZG
P0922ZH
P0922ZJ
P0922ZL
P0922ZM
P0922ZN
P0922ZP
P0922ZT
P0922ZU
P0922ZV
P0922ZW
P0922ZZ
P0923AC
P0923AF
P0923AG
P0923AH
P0923AK
P0923AL
P0923AN
P0923AP
P0923AT
P0923AX
P0923BQ
P0923BR
P0923BS
P0923BT
P0923BU
P0923BV
P0923BW
P0923BX
P0923BY
P0923CA
P0923CB
P0923CC
P0923CD
P0923DA
P0923DB
P0923DC
P0923DD
P0923DG
P0923DH
P0923DK
P0923DN
P0923DP
P0923DR
P0923DS
P0923DU
P0923DV
P0923DW
P0923DY
P0923DZ
P0923FB
P0923FQ
P0923FS
P0923FT
P0923GF
P0923GG
P0923GL
P0923GM
P0923GN
P0923GP
P0923GQ
P0923GR
P0923GT
P0923GW
P0923GX
P0923GZ
P0923HM
P0923HN
P0923HP
P0923HQ
P0923HR
P0923HT
P0923HU
P0923HV
P0923HX
P0923JA
P0923JD
P0923JG
P0923JK
P0923JN
P0923JV
P0923JW
P0923JX
P0923JY
P0923JZ
P0923KA
P0923KD
P0923KL
P0923KP
P0923KS
P0923KV
P0923LH
P0923LL
P0923LN
P0923LR
P0923LU
P0923LV
P0923LW
P0923LX
P0923LY
P0923MA
P0923MB
P0923MC
P0923MD
P0923ME
P0923MF
P0923MG
P0923MH
P0923MM
P0923MN
P0923MP
P0923MR
P0923MX
P0923MY
P0923MZ
P0923NE
P0923NF
P0923NG
P0923NL
P0923NN
P0923NP
P0923NS
P0923NT
P0923NU
P0923PF
P0923PG
P0923PH
P0923PJ
P0923PK
P0923PL
P0923PM
P0923PN
P0923PP
P0923PQ
P0923PR
P0923PS
P0923PT
P0923QF
P0923QG
P0923QL
P0923QM
P0923QS
P0923QT
P0923QU
P0923QV
P0923QW
P0923QX
P0923QY
P0923VA
P0923VD
P0923VE
P0923VF
P0923VJ
P0923VR
P0923VS
P0923VT
P0923VV
P0923ZB
P0923ZC
P0923ZD
P0923ZE
P0923ZF
P0923ZG
P0923ZH
P0924DT
P0924EA
P0924EB
P0924EC
P0924ED
P0924JH
P0926AH
P0926BE
P0926CA
P0926CB
P0926CC
P0926CD
P0926CE
P0926CF
P0926CM
P0926CN
P0926CP
P0926DF
P0926DJ
P0926DP
P0926DS
P0926DV
P0926DZ
P0926EA
P0926EK
P0926EL
P0926EQ
P0926GG
P0926GH
P0926GJ
P0926GQ
P0926GR
P0926GS
P0926GU
P0926GV
P0926GW
P0926GX
P0926HC
P0926HF
P0926HJ
P0926HM
P0926HQ
P0926HT
P0926HW
P0926HZ
P0926JC
P0926JF
P0926JJ
P0926JM
P0926KE
P0926KH
P0926KK
P0926KL
P0926KM
P0926KN
P0926KP
P0926KQ
P0926KR
P0926KS
P0926KT
P0926KW
P0926KZ
P0926LC
P0926MX
P0926MY
P0926MZ
P0926NK
P0926NL
P0926NM
P0926NN
P0926NP
P0926NQ
P0926NS
P0926PA
P0926PS
P0926PT
P0926QL
P0926QM
P0926QN
P0926QP
P0926QS
P0926QT
P0926QV
P0926QW
P0926QX
P0926RV
P0926SP
P0926SQ
P0926SZ
P0926TD
P0926TH
P0926TJ
P0926TK
P0926TL
P0926TM
P0926TN
P0926TP
P0926TQ
P0926TR
P0926VY
P0926WG
P0926WH
P0926WJ
P0926WK
P0926WL
P0926WM
P0926WN
P0926WP
P0926WQ
P0926XA
P0926XB
P0926XE
P0926XM
P0926ZN
P0926ZP
P0926ZY
P0926ZZ
P0927AH
P0927AJ
P0927BA
P0927BB
P0927BC
P0927BD
P0927BG
P0927BH
P0930AS
P0930AU
P0930CA
P0930CB
P0930CC
P0930CD
P0930CE
P0930CF
P0930CG
P0930CH
P0930DA
P0930DB
P0930DC
P0930DD
P0930DE
P0930DF
P0930DG
P0930DH
P0930DM
P0930DN
P0930DP
P0930DR
P0930DS
P0930DT
P0930DU
P0930DV
P0930DW
P0930DX
P0930DY
P0930DZ
P0930EE
P0930EF
P0930EG
P0930EK
P0930EU
P0930EV
P0930EY
P0930FC
P0930FD
P0930FE
P0930FF
P0930FG
P0930FH
P0930FJ
P0930FK
P0930FL
P0930FM
P0930FN
P0930FP
P0930FQ
P0930FR
P0930FS
P0930FU
P0930FV
P0930FW
P0930FX
P0930FY
P0930FZ
P0930HL
P0930HM
P0930HN
P0930HP
P0930HQ
P0930HS
P0930HT
P0930HV
P0930HX
P0930HY
P0930WG
P0931DM
P0931DT