Brand: HITACHI
Category: Other
Document Type: Manual
Language: EN
Manual for CM800U,CM801U,CM802U,CM803U
Uploaded: Nov. 21, 2025, 6:21 p.m.
Manual Publish Date: 1996-08-01
Features:
- Flat screen CRT with anti-glare, dynamic focus circuit, dark glass, and INVAR shadow mask for sharp focus and high contrast.
- Automatic scanning and adjustment for a wide range of frequencies.
- Signal input supports 13W3 Type D-Sub or D-Sub Mini 15pin cables.
- Power Save Mode automatically reduces power consumption when signals are absent (less than 30W in standby, less than 5W in power off).
Safety Precautions:
- Handle the picture tube with extreme care, wearing shatterproof goggles.
- Ensure all protective devices are replaced when servicing.
- Observe original lead dress, especially in high voltage areas.
- Use only manufacturer's replacement components for critical parts.
- Thoroughly test the unit after servicing to ensure safety.
- Microprocessor unit replacement requires shop adjustment.
Troubleshooting and error codes
| PROBLEM | RELEVANT CIRCUITS | SYMPTOMS/CHECKS | ACTIONS/REPLACEMENTS |
|---|---|---|---|
| 1. RASTER DOES NOT APPEAR | Power circuit, Horizontal deflection circuit, High voltage limitter circuit | Check supply Voltage AC100-120V/AC200-240V | Normal: Proceed to next check. Abnormal: Check F901. |
| Check F901 | Normal: Proceed. Abnormal: Replace F901. | ||
| In key mode, 10 seconds after finishing operation, power LED only light. | Yes (Normal): Check +B. Others: (Abnormal) -> No | ||
| The power LED is green. | No: Microprocessor Unit is damaged. Change the Microprocessor Unit. Yes: Sync signal input error. Refer to item 2. | ||
| Check + B (More than 50V, Less than 180V) | Normal: Horizontal drive pulse. Abnormal: Refer to item 2. | ||
| 2. SYNCHRONIZATION IS NOT OBTAINED | Sync. input circuit, Deflection circuit | Turn the FHOH ADJ VR (R724) or FHOL ADJ VR (R721) or FHLL ADJ VR (R726) | Normal: H. Sync. is not obtained. Abnormal: |
| H. sync. or V. Sync. is not obtained. | (1304, 1701, 1702, Q701, Q702, D35Z or D30Z) (Change the C97(B) Video/V Board) | ||
| Microprocessor Unit is damaged or 1703, 1001 | (Change the Microprocessor Unit) | ||
| 3. VERTICAL SINGLE LINE | Horizontal output circuit | DY faulty, Q800, D771, Q764, Q760 | (Change the C97(B) Video/V Board) |
| 4. HORIZONTAL SINGLE LINE | Vertical deflection circuit | Check the Voltage on pin 8 of 1630 (23~25V) | Normal: Others: Check the Voltage on pin 1 of 1630 (13~15V). |
| Check the Voltage on pin 24 of 1701 (3.5V and over) | Normal: (Change the C97(B) Main Board). Others: (Change the C97(B) Video/V Board). | ||
| 5. COLOR DOES NOT APPEAR | Video amplifier circuit | Check the input signal. | Normal: Trouble outside the character monitor. Abnormal: D983, 1981 (Change the C97(B) Main Board). |