Chapter 3---Service Adjustments
3-12
Model 330, 340SC, 370SC Service Manual
9.
Cutoff R and view B.
10.
Repeat Steps 2-4 for Blue.
3.8 Electronic
Focus
The Electronic Focus adjustment is factory-set and should not need to be adjusted.
Whenever a major component has been replaced, like a CRT, or if the high
voltage power supply has been repaired the electronic focus will have to be
readjusted. To do this, select Test Pattern 8, H-GRID, and observe the screen for a
sharp focus at the center of the screen.
If the center appears sharply focused, there is no need to perform the electronic
focus. Follow the procedure below if readjustment is necessary.
NOTE:
The electronic focus adjustment focuses the electron beam in the CRT.
View one color at a time for these adjustments. Recheck the focus of each color
because some interaction between R, G and B may occur. The electronic focus
adjustment panel is located on the High Voltage Power Supply on the left-rear
side of the projector (refer to Figure 3-5).
To adjust the electronic focus:
1.
Press T
EST
1, Test Pattern 8, H-G
RID
.
2.
Cutoff R and B.
3.
Continue with a low resolution source (31.5kHz/60Hz) connected to the
projector inputs and Size is at 100% from the previous CRT Mechanical
Focus procedure.
4.
Using a small plastic screwdriver, adjust the electronic focus for Green
and observe the center of the screen. Have another person watch the center
of the screen up close while adjusting.
NOTE:
Be careful to adjust the E
LECTRONIC
F
OCUS
and not G2. These
adjustments are close to each other and one could be mistaken for the
other. (Figure 3-5).
5.
Cutoff G and view R.
6.
Repeat Step 3 for R electronic focus.
7.
Cutoff R and view B.
8.
Repeat Step 3 for B electronic focus.
