Projector Service Manual

Chapter 3---Service Adjustments
Model 330, 340SC, 370SC Service Manual 3-9
1. Select ILA
®
Menu, from the Main Menu.
2. Select Frequency Adjust from the ILA
®
Bias Menu.
3. A frequency of 1.8 kHz is acceptable for general video viewing. A lower
frequency (as low as 1.5 kHz) will provide a brighter image but with lower
image burn-in. A higher frequency provides higher resolution. For HDTV
a frequency of 2.0-2.5 kHz provides higher resolution. Use the up/down
keys to adjust the ILA
®
frequency for the appropriate input source. As a
general rule 1.8 kHz works well with most sources.
4. Display the ILA
®
B
IAS
M
ENU
again.
5. Select ADJUST, NO VIDEO. Don't attempt ILA
®
Bias adjustments on
Bias W/ Video. This feature is used for factory quality control only.
6. Press GREEN on the remote to select Green. Place lens caps over the Red
and Blue lenses.
7. Use the up/down arrows to adjust the Green ILA
®
Bias until the brightest
area of the ILA
®
image dissappears. Then raise the bias level until the
ILA
®
image just starts to appear on the screen at any point. Finally, slowly
lower the bias level again to the threshold point where the ILA
®
image just
disappears.
NOTE:
It’s crucial for the optimum operation of the projector to set the
bias level to the point where the selected color just begins to appear on the
screen. Find the spot on the screen where the active color first begins to
get brighter and use that as the reference point. Go below and above this
point to find the setting where one (1) click on the UP key causes an
increase in brightness and stop at that point. This will insure that the
weakest video signal will cause the ILA
®
assembly to respond.
8. Cover the Green lens and uncover the Red lens. Press RED to select Red.
9. Repeat Step 7 for the Red ILA® Bias.
10. Cover the Red lens and uncover the Blue lens. Press BLUE to select Blue.
11. Repeat Step 7 for the Blue ILA® Bias.
12. Press Enter on the remote to save the settings and exit this adjustment.
NOTE:
The ILA
®
Bias settings affect other projector settings. When ILA
®
Bias has been adjusted, verify and readjust, if necessary, all projector
adjustments from the appropriate section of the specific model Operator’s
Manual.
3.7 CRT Mechanical Focus
The CRT mechanical focus is factory set and will normally not need to be
adjusted. Whenever a major component (like a CRT or a HVPS) has been
replaced or repaired the CRT mechanical focus must be reset. Use Test Pattern 8,
H-Grid and observe the corners of the screen. If the corners are all in sharp focus,