Up to work out of order, later shut boot and normal cooling later machines one element poor thermal stability, or some components have a virtual welding, plug-ins have poor contact, heated contact disconnected after failure, etc. Fault phenomenon is a light, silent, should be mainly in switching power supply and scanning circuit malfunction. Nrsservice manual download site
(1) online, wait for after failure occurs, test the S1 point dc voltage of 0 v, measuring the switch tube Q801 collector is 280 v. Shutdown instantly by R x 1 S1 Ω gear test point to ground zero resistance, resistance to jump in a minute into 500 Ω, the work after a period of time 111 v load have serious short circuit, the power output. Nrsservice manual download site
(2) the first suspect SCR Q804, boot with electric baking Q804, rapid emergence has fault, get off after Q804 machine back to normal. Replace the new SCR TFD315M, troubleshooting.Nrsservice manual download site