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[backcolor=#ffffff]一台[/backcolor][url=http://www.jdwxs.com/hx/]海信[/url][backcolor=#ffffff]LED55K310X3D[/backcolor][backcolor=#ffffff]通电后不开机,指示灯微亮,拆壳测量电源板(RSAG7.820.4763)上5V只有2.85V摆动.续查12V只有4.68V不稳, 16V为基本为0V,且细听电源有轻微的吱吱声,无疑电源负载过重或有负载有短路地方,于是拨下主板(RSAG7.820.5142)与电源之间的排线,重测电源依旧.问题出在电源就好修多了.直去16V负载后测得16V肖特基整流二极管D815(图标MBR5H150 实际用245G515VP (5A/150V))严重发热.取下测之正反向阻值几乎等于零.由于手中没有肖特其二极.就用UF5408(3A/400V快恢复管)试替代.工作长时间手摸其温度微热,看样子UF5408可以替代.
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