海尔电视维修实例（A case of haier TV maintenance）.doc

海尔电视维修实例（A case of haier TV maintenance） Haier TV service instance (A) machine model 29 fv6 - A fault phenomenon: the upper level bright line up and down shaking screen repair measures: change the deflection coil analysis maintenance: check field power supply circuit R414, D402, found apparent R414 yellowing phenomenon, disconnect measurement R414, D402 has been damaged, shows A negative... A case of haier TV maintenance (a) Machine model 29FV6 - A Fault phenomenon: the upper part of the screen has horizontal bright line up and down Maintenance: replace the deflection coil Analysis maintenance: check field power supply circuit R414, D402, found apparent R414 yellowing phenomenon, disconnect measurement R414, D402 has been damaged, a load circuit exists the phenomenon of short circuit, the multimeter resistance measurements, the road has no obvious damage components, integrated circuit TDA8177 substitution field, to replace the damaged R414, D402 boot, fault, still touch resistance R414 temperature rise gradually. On each foot TDA8177 voltage measurements found 4 feet voltage is zero, the deflection coil disconnect measurement field integrated circuit power supply voltage returns to normal, prove there is short circuit phenomenon, deflection change deflection of commissioning. (2) Machine model: D29FV6 - A Failure: 3 cm wide in the middle of the working 4-5 hour image. Maintenance measures: change C303 to 2200P porcelain chip capacitance Analyze maintenance: this phenomenon belongs to the component thermal stability is poor, failure occurs voltage measurement TDA8177 each foot has no obvious change, try substitution field capacitance C306, C302, C303, C308 commissioning failure remains, the experiment of this machine from the change of ambient temperature change with the time of failure occurs. Use the heating method to repair, the electric chromium iron test to the field circuit element heating, when add to C303, the fault appears, replace C303 capacitor test machin