卡特312c挖掘机驾驶室里显示屏不亮是什么原因

select tdid,khrq,cm,hc,tdh,zhg,jhdd=(case when (mdd is null or mdd='') then (case when (jhdd is null or jhdd='' ) then xhg else jhdd end) else mdd end), yqddrqsj=(select top 1 yqddrqsj from tdzxd where tdid=cmhctd.tdid),kfcz=(select zwmc from hysys..ry where rymc=cmhctd.kfry), dcdwmc=(select top 1 mc from wlh where dm=cmhctd.dcdw),prevw,jsxx=(ltrim(str(js))+' '+isnull(bzxsywmc,'')),mz,tj, gsdz=(select value from sys where name='gsdz' and lb='用户'),convert(varchar(10),getdate(),20) as today, gslxrdh=(select value from sys where name='gslxrdh' and lb='用户'),zxpx, gsfax=(select value from sys where name='gsfax' and lb='用户'), hxdh=(select top 1 bgdh from tsdhxd where tdid=cmhctd.tdid and bgdlb='核销单'), usjje=(select isnull(sum(sjje),0) from yf where tdid=cmhctd.tdid and ysyf='应收' and bz='USD' and wlhdm=(select top 1 dm from dw where mc='@wlhmc@')), rsjje=(select isnull(sum(sjje),0) from yf where tdid=cmhctd.tdid and ysyf='应收' and bz='RMB' and wlhdm=(select top 1 dm from dw where mc='@wlhmc@')), jzsjje=(select isnull(sum(sjje),0)*6.4000 from yf where tdid=cmhctd.tdid and ysyf='应收' and bz='USD' and wlhdm=(select top 1 dm from dw where mc='@wlhmc@'))+ (select isnull(sum(sjje),0) from yf where tdid=cmhctd.tdid and ysyf='应收' and bz='RMB' and wlhdm=(select top 1 dm from dw where mc='GOLDFAME ENTERPRISES(INT'L)KNITTERS LTD')) from cmhctd where tdid in (06536)