In the selection state of the band switching voltage measured normal to determine tuner damage. The aircraft tuner is "active low", that is when the band receives a switching voltage is low 0V, the rest of the band switching voltage is high, contrary to the common C-type tuner. The tuner model TECC2984VD28A, selected Tesco, inexpensive C-tuner, plus a small number of components to substitution. As follows: The C-type tuner housing four little plastic ground pin, unless IF function outside the rest of the foot foot bend 90 ° from the roots of some valuables after each external line about 5cm, insert the ground floor and weld the legs and feet IF fixed. In the copper surface by drawing on resistance welding three PNP silicon transistor and three 10kΩ or so, and with good access to the corresponding pin. The example chosen is "Shanghai Himage" tuner. Although its operating voltage of 12V, but it is 9V power supply when the original machine is still working.6jVservice manual download site