The machine USES CT972 + CT970 motherboard, panel keying circuit matrix HT6221 block as the core. After the machine engine failure, does not exclude the virtual welding circuit or element of poor thermal stability. Due to the remote control has always been normal, show that the problem can only be a keying circuit. CSsservice manual download site
 CSsservice manual download site
In the process of machine to work properly, the fuselage vibration tapping panel and press, and failure did not appear, that failure is not caused by welding. In order to in the shortest possible time to determine the specific fault components, use hair dryer heating tubes on the panel, respectively 455 KHZ crystals, HT6221, etc. When heated to block keying HT6221 fault immediately appear, using alcohol to its cools, keying and returned to normal, HT6221 adverse. CSsservice manual download site
 CSsservice manual download site
 CSsservice manual download site
Because of no HT6221. Try D6121GOOI direct substitution, keying operation is normal, and the fault is no longer present.CSsservice manual download site