General frame to frame a line fault output IC, the power supply circuit, an oscillator called damage is common. This machine is powered by a normal investigation , ic601 53 feet oscillation waveform output is normal , IC451 also working point of the foot with an external signal injection IC451 1 foot grating appeared , so the focus of suspicion interface circuit IC401 failure problem , check the frame waveform really 17 feet no output , input is normal , and check their peripheral bus voltage operating point of each foot and no abnormalities, failure seems to be very clear , IC401 damaged, but replaced the IC401 fault persists, maintenance deadlocked.RXeservice manual download site
 RXeservice manual download site

After careful examination blueprint analysis IC401, feel the impact of the internal frame signal at IC401 -off only bus actions, and subsequently review the bus voltage is normal , with an oscilloscope to see , even without waveforms along the check to the computer block IC1101 of 37.38 feet no wave , does not block the work of the computer ? carefully check IC1101 working conditions, found 25 feet RESET voltage of 0.5 volts, this pin is disconnected peripheral resistance as measured on the ground of its 3 ohms , significantly short circuit !RXeservice manual download site

So far, after replacing the IC1101 MN1873284TF1 troubleshooting . We see from this example , the repair time bus voltage measurement circuit has not, have combined to determine the wave , so take some detours .RXeservice manual download site