Samsung ML-7000N, Руководство по обслуживанию

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5-5 .Troubleshooting of Video Controller
Most electronic products are sensitive to connectors and assemblies that are not complete seated. Therefore, before
starting the troubleshooting procedure, do a mechanical check of all the connectors and assemblies to make sure that
everything is properly seated.
1. For a complex malfunction, check first for a bad weld, short circuit or loose wire on the solder area of the board
2. Input low level is standard for the TTL logic level below 0.8V.
Input high level is standard for the TTL logic level above 3.5V.
But, for PowerPC 603e, the input low level is less than 0.8V, and the input high level is more than 2.0V.
3. USE an oscilloscope or logic analyzer for inspecting the crystal oscillator or its waveform.
5-5-1. Troubleshooting Flow Chart
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