+ B measurement is 160 V, 130 V, the other three groups power 6.5 V, 14.5 V and 15 V voltage are volatile, such as 15 V group swings between 5 V to 15 V. Analysis of 130 v + B increased to 160 v is the main reason lead to the machine is in a state of protection. Because there was no circuit diagram, so the concentration check voltage switch power supply part. First in benchmark IC TL431 is invalid, again in light coupling also invalid, check voltage sampling resistance, which remove the R815 five-color loop resistance, according to their color ring should be 127 k Ω, but Ω measured at 320 k. Because can't find the 127 k Ω resistance, with 100 k Ω + 27 k Ω power larger resistance change. Boot + B 130 v stable normal, troubleshooting.KYUservice manual download site