Dell 2145cn, Service Manual

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Alignment and Troubleshooting
4-42
■ Machine Test
SWITCH TEST
Use this feature to test all keys on the operation control panel. The result is displayed on the LCD
window each time you press a key.
MODEM TEST
Use this feature to hear various transmission signals to the telephone line from the modem and to
check the modem. If no transmission signal sound is heard, it means the modem part of the main
board malfunctioned.
DRAM TEST
Use this feature to test the machine’s DRAM. The result appears in the LCD display.
If all memory is working normally, the LCD shows << O K >>
ROM TEST
Use this feature to test the machine’S ROM. The result and the software version appear in the LCD
display.
SHADING TEST
The function is to get the optimum scan quality by the specific character of the CCD(Charge
Coupled Device). If the copy image quality is poor, perform this function to check the condition
CCD unit.
< Method >
1. Select the [Machine Test-Shading Test] at the TECH MODE.
2. Push the SET UP button then an image will be scanned.
3. After the scan, CCD SHADING PROFILE will be print out.
4. If the printed image is different to the image, the CCD is defect.
NOTICE : When you test CCD, make sure that the cover is closed.