Service manual

4. ADJUSTMENT

4-1 ADJUSTMENT CONDITIONS AND PRECAUTIONS

1. Approximately 30 minutes should be allowed for warm up before proceeding.

2. Adjustments should be undertaken only on those necessary elements since most of them have been carefully

preset at the factory.

4-2 MAIN ADJUSTMENTS

NO.

FUNCTION LOCATION DESIGNATION

1. B + ADJ PCB - MAIN VR902

2. SCREEN ADJ FLY BACK TRANS T402

3. FOCUS ADJ FLY BACK TRANS T402

4. ABL ADJ PCB - MAIN VR701

5. SUB-BRIGHTNESS ADJ PCB - MAIN VR702

4-3 ADJUSTMENT METHOD

1. B + & HV voltage adjustment and hold down circuit confirmation:

A. Chrome-2000 Signal generator or PC equivalent set mode 5, VGA 1024X768@85Hz pattern 1 .

B. Connect a DC Volt meter between TP902 or D925 cathode and ground, then adjust VR902 to be

133VDC(B+).

C. Connect a DC Volt meter between TP701(G1) and ground, Brightness set to max. Then adjust VR702 to

be -30 VDC.

D. Connect a 22kΩ resistor in parallel with R419 to increase the HV, the hold down circuit will operate and

the display will disappear. Then disconnect this resistor to bring the unit to normal condition.

2. Factory preset Timings Adjustment:

A. Press MENU Key to show OSD window press Up or Down Key to switch the functional controls.

B. Press the Up Key to select the "ZOOM" function, then press the MENU Key. While do not release the

MENU Key until the OSD window changed to the Factory preset window.

C. The Factory preset window contains the following functional controls. Select one of the control by press

MENU key. Then press the Up/Down Key to adjust it's value for the optimum picture.

MENU Key to Quit the OSD window. Mean while the new setting data will be saved in the memory.

E. To switches the input signal to the other Timing Mode. Please follow step C ~ D to get the optimum picture.

F. Select the "

" RETURN function and press the MENU Key, then the Factor Preset window will be

returned to the original OSD window.(user's operating condition)

G. The setting data of the CONTRAST, BRIGHTNESS, PIN-BALANCE, PARALLELOGRAM,

ROTATION, COLOR TEMPERATURE are common mode saved in the memory. Don't needed adjust it

individual at every timing Mode and save in the memory.

Model select: for factory only, service engineer can't changed.