Video Troubleshooting Table
| SYMPTOM | CAUSE |
| REQUIRED ACTION |
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| Verify connection of AC Power to video monitor. |
• | Monitor appears non- | Power problem |
| Inspect CRT neck in dim light. Glowing filament |
| functional |
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| near CRT base proves that some monitor |
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| circuits receive power. Still, voltages or signals |
• | Audio is present |
|
| may not be normal. |
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| 1. Turn off VGM power. Verify that video signal and | |
• VGM (video game machine) | Faulty wiring |
| Remote Adjustment Board connectors seat | |
| controls operate normally |
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| properly on Video Monitor Board. |
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| 2. Assure that video cables connect to circuit | |
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| boards and computer. |
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| 3. Assure that no wires are caught on chassis or | |
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| mounting brackets. |
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| Improper monitor |
| Check that BRIGHTNESS (intensity) and |
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| adjustments |
| CONTRAST are set above their minimum levels. |
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| 1. Examine AC line fuse on Video Monitor Board. If | |
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| Faulty monitor |
| fuse is faulty, replace it with identical fuse. |
|
| circuitry | 2. | If fuse is good: Verify that video monitor |
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| operates correctly by placing it in working VGM. |
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| 3. If monitor is bad: Check monitor power supply. | |
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| 4. | If power supply is good: Check monitor |
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| horizontal output transistor and related circuitry. |
WARNING: HIGH VOLTAGE. VGM (video game machine) monitors generate and store potentially lethal high voltages. Avoid touching any part of the monitor until power has been off for some time. A picture tube can maintain a hazardous charge for up to several days. Only qualified technicians should service monitors. Turn off the power, unplug the VGM and discharge the CRT before attempting service. Even properly discharged tubes can revert to a highly charged state, without reapplication of power.
WARNING: In normal operation, the monitor doesn’t require isolation from AC line voltage. During bench servicing, you may need to operate the monitor outside the cabinet. If you do, isolate the monitor from line voltage with an isolation transformer.
Troubleshooting