According to the fault phenomenon, it is estimated that the performance of a part of the circuit is changed after heating, or the contact is bad. Sync separation part of the machine in the DG in, because of the confidential boot about 2 hours before failure, available local heating method and promote failure. When the image is normal, use the hair dryer to heat the DG plate, and when the DG plate is blown to the upper right, the image is not synchronized, remove the hair dryer, and the image is quickly restored. The upper right DG board of IC8004, the IC is a synchronous signal processing function, because the hair dryer blowing range is too big, not easy to determine the fault components, with a hot-air gun, small volume, adjust the temperature to the right degree, when C1886/C1887/C1888 IC8004 and several blows to the next element, fault appeared in 3 seconds in high precision, use cotton dipped in alcohol posted on IC8004, at the same time to the above several heating chip capacitors (to avoid IC8004 effect, heating judgment) or soon failure, the fault range only in several SMD capacitors, because several chip power volume is too small, hot air gun or unable to determine the specific parts, the use of electric the iron tip heating, when the iron tip contact to C1887, immediate failure, remove the iron head and soon returned to normal, the other capacitor has no reaction, that is C1887 after heating bad performance. After the replacement of C1887 (10u/6.3v), troubleshooting.