From the failure phenomenon , the other normal . Only light without heating , indicating that the light pipe related circuit failure , local failure are:3Pvservice manual download site

( 1) The light tube is damaged . Multimeter to measure resistance values ​​available light tube , if the 20Ω-300Ω as normal, or infinity if 0n was greatly damaged, you can replace troubleshooting .3Pvservice manual download site

( 2 ) light relay coil open GRILL , R43 resistance becomes larger . Relay GRILL not pull its contacts RY2 not closed, cutting off light tube circuits , light does not heat . Measured with a multimeter relay coil resistance is 320Ω,, if it is infinite , indicating the coil circuit . First through the relay coil outer insulation shell observed whether the scorch marks , if the outer insulation is good, then the fault is multi- pin solder sealing off the outer layer of the coil due to mildew or broken . Pry out the relay housings, insulation paper to observe the lift pin , can be found coil break , weld tin can . Resistor R43 resistance becomes large, so that in series with the relay GRILL. Pull coil circuit current decreases , causing the relay coil voltage is less than 12V CRILL lot , can not pull its contacts RY2 not closed , lightwave circuit is cut off without heating. Replace the resistor R43 ( resistance is 15Ω).3Pvservice manual download site

( 3 ) transistor Q5 open ; R15 resistance becomes larger ; D4 leakage . Q5 open. GRILL cut relay coil circuit , not pull, lightwave circuit is cut off ; resistor R15 resistance becomes larger , so not suitable conduction Q5 base bias and cut , cut off lightwave circuit ; diode D4 leakage, if measured with a multimeter positive and negative resistance are small, about 40Ω; or smaller reverse resistance , the relay coil is not suitable CRILL pull-in voltage (<12V), contact RY2 not closed , cutting off light tubes H circuit , light tube without heating , replacement of damaged components to troubleshooting .3Pvservice manual download site