According to the maintenance experience, into the integrated circuit IC101 (AN5138) virtual welding easy to appear the fault, observe the IC real virtual welding, commissioning after repair welding failure remains. From VCD video terminal input signal, the observation screen still has interference, failure is nothing to do with putting IC. Due to the machine without drawing, causing inconvenience to maintenance, by checking the panasonic TC - 2185 color TV sets drawings with the similar, therefore, refer to the machine drawings for maintenance. Check channel video and brightness, check brightness delay LC301 normal, measuring IC601 (AN5601K) brightness control {and} feet does not change with the fault voltage of 2.8 V, suggests that fault has nothing to do with the brightness adjustment circuit. Will contrast potentiometer components under welding cleaning, installed after the failure of the same, change the maintenance switch S601 invalid, decoding block IC601 bad suspicion. Measure voltage, maintenance switch (4) feet unintentionally found that uncertainty, the foot is by controlling the opening scanning circuit break for CRT white balance, there is a triode O602 beside the maintenance switch, measuring the voltage over failure in 4 b v ~ 8 v change, between the triode is different from ordinary triode, is rejection triode H4111, welding measure has leakage, depending on their location confirmed by maintenance switch to control the work of field scanning circuit or not to proceed with the white balance adjustment, normal watch don't have to, because have no the tube, so no commissioning, troubleshooting.HBcservice manual download site