Faroudja VP251 Installation instructions

“Perfecting Video with a
No-Compromise Approach
for Reproducing
the Ultimate Film Experience”
The Faroudja
VP251 Video Processor
With Picture Plus™Technology
Installation & Operation
Instructions
™

History . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
Licensees and Awards. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
System Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
Inventory List . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
Caution Notes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
Technical Highlights . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-7
Installation Instructions. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
Operating Instructions. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-10
Troubleshooting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
Appendix A: RS232 Programming Instructions. . . . . . . . . . . . . . . . . . 12-13
Remote Control Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
Cable Specifications. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
Specifications. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
Copyright©1998 by Faroudja Laboratories, Inc.
No part of this document may be copied, photocopied, reproduced, translated, or reproduced by any electronic
medium or machine readable form without prior consent, in writing, from Faroudja Laboratories, Inc.
The Faroudja Laboratories VP251 Line Doubler is covered by the following United States patents: 4,030,121,
4,179,705, 4,240,105, 4,262,304, 4,847, 681, 4,864,389, 4,876,596, 4,893,176, 4,916,526, 4,967,271,
4,982,280, 4,989,090, 5,014,119, 5,025,312, 5,159,451, 5,237,414.
All Rights Reserved.
TABLE OF CONTENTS

HISTORY
Faroudja Laboratories, located in northern Califor-
nia’s Silicon Valley, was founded in 1971 by Yves
and Isabell Faroudja to develop state-of-the-art
video processing technology. Over the last 26
years, Faroudja Laboratories has developed
hundreds of advanced electronic processes to
improve video enhancement, noise reduction and
NTSC encoding/ decoding technologies. Many of
these processes are used under license by
the world’s leading electronics companies in a
wide range of high performance video products.
Faroudja professional video equipment is also
currently hard at work in hundreds of television
studios. Thus Faroudja technology is utilized and
enjoyed in millions of American homes every day.
Yves Faroudja has devoted his career and his
company to the goal of enabling home video
systems to achieve the image quality of 35mm
2
motion pictures. In pursuit of this goal, Faroudja
Laboratories has made use of techniques from
Faroudja professional video equipment and incor-
porated these in the VP251/VP201/VP201U/ line
doublers, VP301 line multiplier and the 401/VP401U
line quadruplers. Faroudja’s unique approach
focuses on critical problem areas in the NTSC and
PAL broadcast format. With patented engineering
and design work, Yves and Faroudja Laboratories
have created an exceptional product that brings
new levels of visual reality to the enjoyment of dis-
cerning video enthusiasts around the world.
This booklet will provide the reader with a hands-on
look at the VP251, its operation and benefits.
Also supplied is an overview of the proprietary tech-
nologies utilized in this extraordinary device and an
explanation of the visual improvements it provides
in home video and corporate playback systems.
Some Video History and the Faroudja Approach
This manual is for use with the VP251 which handles both NTSC and PAL sources. For simplici-
ty the documentation references NTSC. All instructions for installation and operation are the
same for PAL sources

LICENSEES AND AWARDS
1987: SMPTE
DAVID SARNOFF GOLD MEDAL AWARD
for
“Contributing to Optimizing NTSC Performances”
1988: MONITOR AWARD
for
“Excellence in Engineering
NTSC Encoders and Decoders”
1989: BM/E AWARD
for
“Excellence in Engineering”
1991: Technology Executive of the Year
from Cable TV Business
1991: EMMY
from The National Academy
of Television Arts and Sciences
for
“Techniques for Minimization of NTSC Artifacts
Through Advanced Encoding Techniques”
1992: VIDEO GRAND PRIX AWARD
Audio/Video International
LD100 Line Doubler “Advanced Technology Award”
1993: VIDEO MAGAZINE
Video Visionary
1995: BROADCAST ENGINEERING AWARD
1997: VISUAL GRAND PRIX AWARD
Audio Video Review Magazine (Japan)
LD200
1997/1998: RECOMMENDED COMPONENTS
Stereophile Guide to Home Theater Magazine
AAA Rating: VP250, VP400A
1998: PLATINUM AWARD
AV Video Multimedia Producer Magazine
Outstanding Achievement: VP250
3
Licensees Around the World
Faroudja’s inventive approach to improving the
quality of video imaging has caught the eye of
some of the world’s greatest high technology com-
panies. The following list represents those that
have recognized the value of Faroudja’s solutions
to imaging problems and pay for the opportunity to
incorporate this technology in their advanced video
products (as of January 1998):
Canon Microtime
Conrac Mitsubishi
General Instrument NAC
Grass Valley NEC
Hitachi Sanyo
Ikegami Sharp
JVC Sony
Matsushita (Panasonic) S3
Toshiba
Awards and Achievements
Yves Faroudja and Faroudja Laboratories have
garnered worldwide recognition and a number of
industry awards. These honors are notable for
several reasons. They are in response to the sig-
nificant impact that Faroudja’s technology has
made on the serious improvement of video quality.
They are also a reflection of his long term dedica-
tion to continually improving and optimizing the
performance of the NTSC and PAL video formats.
On June 24, 1998 Yves Faroudja
was awarded the prestigious
Charles F. Jenkins Lifetime
Achievement Award from the
Academy of Television Arts &
Sciences for his video processing
technology. Faroudja’s first Emmy
was awarded in 1991. Some of this

The Faroudja VP251 Line Doubler/Video
Processor is a precision video instrument used to
convert NTSC interlaced signals into 480 visible,
progressively scanned lines (640X480 resolution).
Using Picture Plus™ technology, the VP251
removes typical video processing artifacts while
also increasing color purity and image detail,
closely matching 35mm film.
The VP251 is designed as an ideal match for
Data-Grade 7” CRT projectors requiring high reso-
lution images while also increasing the projector’s
light output. It is also an ideal match for DLP, LCD
projectors, Plasma displays and computer moni-
tors that require high quality, progressively
scanned signals.
Front panel features include Power, Input Select,
Brightness, Contrast, Color, Tint, and Detail. All of
the settings are automatically stored when the unit
is turned off. Also, up to 32 custom presets can be
set. All front panel features can be adjusted by
infrared and RS232 remote control.
Inputs include: Composite Video, S-Video
Component (Y,Cr,Cb/RGB) and Computer/HDTV.
The Video input may be connected by either a
BNC connection or a video RCA type connection.
These inputs are looped internally so that other
devices may use the signal.. The S-Video input
uses a standard 4-pin connector.
The VP251 requires a standard P15 to RGB
breakout cable when using the component input.
If the looped inputs are used, these cables should
be kept short (under 6' in length) or a video distrib-
ution amplifier should be used. This allows the
VP251 to keep the highest signal bandwidth possi-
ble without having the high frequencies being
attenuated in a long cable.
Output from the VP251 is provided by six BNC
connectors as well as one 15 pin ‘D’ connector.
The BNC outputs provided are Red, Green, Blue,
Horizontal Sync, Vertical Sync and Composite
Sync. Interface to monitors/projectors can be a 4
or 5 wire connection. The VP251 is capable of dri-
ving a monitor/projector using the BNC outputs as
well as a 15 pin ‘D’ connector, at the same time.
The monitor and projector must be compatible with
a 31.5KHz Horizontal scan rate.
4
SYSTEM DESCRIPTION

Circuit Description
Figure 1 is a block diagram of the VP251 showing
signal flow and the location of front panel controls
and switches. Composite Video and S-Video
inputs are connected to the decoder with AGC
control and converted to Y, R-Y and B-Y signals.
The Y, (Luminance) output from the decoder
enters the input switcher while the R-Y and B-Y
signal enter the Chroma Enhancement block
where the Tint phase can be adjusted when select-
ed in the manual mode. The RGB input signals are
transcoded to Y, R-Y, and B-Y signals and fed to
the input switcher. Component signals are fed
directly to the input switcher.
The input switcher then selects the correct function
and outputs the Y signal to the Luminance Line
Doubler block. The Luminance Line Doubler block
contains the Brightness, Contrast and Freeze con-
trols while the R-Y and B-Y signals enter the
Chroma block where the color level can be con-
trolled along with the Freeze controls. The Line
Doubler Luminance signal now enters the
Luminance Detail and Noise Reduction block
where the functions of Noise Reduction and
Detail Level are controlled.
The Luminance signal from the Luminance Detail
and Noise Reduction block along with the R-Y and
B-Y signals from the Chroma Line Doubler block
feed the output transcoder and are converted
to RGB signals. These RGB signals are buffered
and then sent to both the BNC and monitor
output connectors.
When using the RGB or Component inputs, Sync
is derived from the G or Y input signals unless
sync is provided to the Composite Sync input. The
Composite Sync input will override the sync from
the G or Y inputs. The sync signal then feeds the
VP251 clock generator and is used as a reference
to generate Horizontal Sync, Vertical Sync and
Composite Sync.
Inventory List
1VP251 Digital Video Processor
1 Installation/Operation Manual
1 Warranty Card
1 Power Cord
5
SYSTEM DESCRIPTION
Caution Notes
Do not connect the VP251 to a Monitor/
Projector not capable of the correct scan
rates. (31.5KHz)
High Voltages are present inside. Opening
the unit will void all warranties.
No user serviceable parts inside.

Picture Plus™ Technology – The VP251 is called a Line Doubler. However, just increasing the number of lines can
make the image worse. This is where Picture Plus™ technology becomes critical. Picture Plus represents a complex,
multi-stage process that takes advantage of all the patented Faroudja circuitry for color, motion and detail processing.
How these circuits improve the picture are outlined below.
6
STAGE A COLOR PROCESSING: Chroma Bandwidth
Expansion + Adaptive Comb Filter + Cross-Color
Suppression
COLOR BLURRING – The engineers of the 1940’s (and
the 1950’s, before and during the development of color
broadcasting), had no idea that video images would one
day be blown up as large as they are today. They there-
fore designed the color section of the NTSC standard
with severe bandwidth restrictions. This causes colors in
various video images to “blur” and “smear”. These effects
are further aggravated by storage media such as VHS
tapes, that further degrade the chroma or color signal.
e.g. – note how deep reds smear on VHS tape images.
The Faroudja VP251 utilizes proprietary circuitry to
recreate and further correct color details. Technically,
this is accomplished by making use of the sharper black
and white transitions to develop a correction signal
that is then used to sharpen the color transitions. The
result is colors that are restored with sharp details and
video images that retain their original crisp look.
RAINBOW PATTERNS – When you notice the fine
detail of a striped referees shirt rippling with colored
rainbows as the camera pans by, you’ve seen video
cross-color interference.
This annoying artifact is caused by imperfect separation
of the color (chroma) and black and white (luminance)
signals, by the color decoder circuitry. Simple tech-
niques used commonly to separate the two signals can
be effective most of the time but occasionally are fooled
by finer pitch detail areas like the referee’s shirt. The
VP251 has patented cross color suppression that elimi-
nates decoding errors of this type and enables the
reproduction of sharper, cleaner color images.
DOT CRAWL and HANGING DOTS – This phenomenon
is easily seen with large, highly colored, stationary
graphics like titles and credits. Dot crawl is a rapid
upwards movement of colored dots on sharp vertical
transitions. Hanging dots lie underneath all the colored
horizontal transitions. Both of these color aberrations are
artifacts that appear due to an imperfect color decoding
process. The VP251 has an adaptive comb filter that
eliminates both of these distortions. The impact is color
transitions that are clear, sharp and natural.
STAGE B LINE PROCESSING: Film/Video Motion
Tracking
THE VP251 Patented Line Multiplier: eliminates VISIBLE
SCAN LINES – The secret of the VP251’s uncanny abili-
ty to increase the lines of information without adding digi-
tal artifacts is in its unique ability to detect motion and
interpolate correctly. The Faroudja VP251 does this
thanks to its proprietary, patented circuitry. It can detect
the difference between a film image that has been trans-
ferred to video or video image that emanated from a
video camera. After detecting the image type, the VP251
adjusts its algorithm to compensate accordingly.
This is critical because today’s home theaters are pri-
marily used to show films that were transferred to video
whether on tape, laserdisc or off the air (virtually all
prime time programs are film transferred to video). The
VP251 offers sharper, uniquely clean, artifact-free film-
like images without visible scanning lines.
Again, historically speaking, electrical engineers in the
1940’s knew the resolution of a picture tube was depen-
dent on two different mechanisms. Horizontal resolution
is a function of bandwidth (frequency response) of the
TECHNICAL HIGHLIGHTS
SYNC
OUT
R OUT
G OUT
B OUT
Y
R-Y
B-Y
Y
R-Y
B-Y
VIDEO
IN
DECODER LINE
DOUBLER BANDWIDTH EXPANDER VGA
OUT
ABC
Y/C IN
RG B R-Y B-YY
VP251 BLOCK DIAGRAM
MONITOR
MONITOR

7
circuitry, while vertical resolution is a function of the
scanning frequency (the number of scan lines in each
picture). Given these mechanisms and with an average
size picture tube of 8-10”, they designed the 525 line
broadcast standard so that viewers would not see the
scan lines when watching TV. They had no idea that
someday people would be projecting home theater
video images with diagonal screen sizes of 10’ and
more.
Based on those NTSC parameters, using a 10 ft. diago-
nal screen would require the viewer to be located more
than 45 ft. from the screen to see the picture as it was
intended without scan lines! Unfortunately, today’s large
screen installations have scan lines that are quite visi-
ble, especially with some of the latest high resolution
monitors and projection televisions. The VP251 elimi-
nates this problem by scan doubling the 525 interlaced
lines (only 480 lines are actually visible) to become 480
progressively scanned lines. The result is the elimination
of visible scan lines and increased brightness and detail.
The image produced by the VP251 is virtually film-like in
detail, motion and color.
STAGE C DETAIL PROCESSING: Luminance
Bandwidth Expansion
There is a major limitation with most contemporary pro-
gram sources — lack of frequency response. The best
video sources such as satellite dish reception and
laserdiscs can provide acceptable resolution (400 plus
lines of horizontal resolution). Other more common
sources however, such as VHS tapes (230 lines), are
clearly deficient. The problem is compounded when the
scan lines are doubled along with other signal process-
ing. The lack of high frequency detail becomes very
obvious when the more common sources are used.
The resultant picture is free of scan lines but dull, with a
serious loss of definition. The solution is to expand the
high frequencies without producing annoying and picture
degrading artifacts.
The bandwidth expansion circuitry in the VP251 is
exceptionally sophisticated, using Faroudja’s double dif-
ferentiation techniques to sharpen the edges of both
horizontal and vertical details. The result is a sharply
detailed image that appears crisp and three dimensional
with no visible negative side-effects. This process can
effectively double the perceived bandwidth and there-
fore the resolution of the incoming signal.
FAROUDJA VP251 APPLICATIONS – While the tech-
nical accomplishments of the VP251 represent years of
intense research and development, its use is straightfor-
ward and direct. The block diagram (above) illustrates a
typical home theater system configuration and shows
how the VP251 would be inserted in the signal path.
Many entertainment sources benefit greatly by the
VP251’s unique attributes; laserdisc, VHS video, S-
VHS, DVD, cable TV, broadcast TV, etc. The VP251 has
proven to be an invaluable tool in other presentation dis-
ciplines where image quality is important; computer data
displays, professional installations in boardrooms and
media rooms, military installations, government agen-
cies and academic uses in schools and colleges. From
the quality of its individual parts to its state-of-the-art
patented circuitry, the VP251 is truly in a class by itself.
There is simply no finer video processor available.
VIDEO
TUNER
LASERDISC
PLAYER
VCR
VIDEO SWITCHER
VIDEO PROCESSOR
YCRGB SYNC R-Y
B-Y Y
CRT
PROJECTOR
WITH 7'' LENSES
OR
DLP
PROJECTOR,
PLASMA,
COMPUTER
MONITOR
Monitor
COMPUTER
DISPLAY
COMPOSITE
VIDEO
R
G
B
SYNC
/
TYPICAL VP251 SYSTEM UTILIZATION
VP251

Unpacking
Remove the VP251 from the shipping container
and examine it for any signs of shipping damage
or missing items, (check inventory list on page 5).
All shipping materials should be saved if the unit
is to be moved or should need to be returned for
service or repair.
Installation
The VP251 is designed to be placed on a table or
rack mounted. If the rack mounting installation kit is
to be used, the rack mount ears are installed by
removing the 4 ears using the 4 screws. Remove
the four feet from the unit. When installing in a rack,
it will be necessary to support the unit by using rack
support rails supplied by the rack manufacturer.
Do not support the unit by the rack mount ears
alone! Contact Faroudja to order rack kits.
Ventilation
The VP251 will require that air flows freely through
both the bottom and top vent holes. Blocking these
holes will greatly reduce the reliability of the unit
and lead to the possibility of overheating.
When the unit is rack mounted, a minimum of
1.25" (1 rack unit height) of free space is to be pro-
vided for both the top and bottom of the unit to
allow for proper cooling. It is also recommended
that the rack be forced air cooled.
Figure 2
Rear Panel I/O
11. Composite Video Input
12. Composite Video loop-through
(Auto-terminating)
13. S-Video Input
14. S-Video Loop-through (Auto-Terminating)
15. YUV/RGB input (requires D15 to RGB breakout
cable)
16. D9 connection for RS232
17. Computer/HDTV input
18. D15 monitor connection
19. BNC Video output connectors
10. External infrared sensor plug 1/8” stereo jack
11. Power Input
8
INSTALLATION INSTRUCTIONS
Figure 2
679
811
10
1432 5

9
The VP251 Control panel
On-Screen-Display On-Off
Simultaneously press the Factory and Preset 1 buttons
Selecting a push button control lights the adjacent LED to
indicate activation or selection of that particular function.
1) Power ON/OFF – Press the button and the LED lights
green to indicate POWER ON. When the VP251 pow-
ers up it is automatically set to operate just as it was
when it was last turned off.
1) Power ON/OFF – Another push on the switch and the
power is cut off extinguishing the green LED. The
Freeze Circuit is automatically disengaged, if in use,
upon turn off.
INPUT SELECTION SWITCHES
Press to Select
2) Computer/HDTV.–.This control refers to any high reso
lution source such as HDTV or computer signals con
nected to the D15 input. Signal is “passed through” to
the D15 and BNC outputs. The signal is not
processed by Faroudja circuitry.
3) Video – refers to any composite NTSC video signal -
(e.g. VCR’s, laserdisc players, cable boxes, etc.)
4) S Video – refers to any source that outputs S-Video
signals (DVD, S-VHS, satellite receivers, etc.). Using
the input allows one to realize all the benefits of main-
taining the separation of the luminance (picture) and
chrominance (color) signal through the video signal
processing chain, thus avoiding rainbow patterns and
dot crawl.
VIDEO PROCESSOR OPERATING INSTRUCTIONS
1
3
15
16 4
7810
911
13
12
2
14
5 6
5) RGB – refers to the incoming video signal broken
down to the individual red, green and blue format more
typically found in the professional and broadcast area.
6) Component Input – refers to the video signal
in its component form (Y, R-Y, B-Y or Y, Cr, Cb for
DVD) carried in a 3-wire cable.
7) Brightness – The Brightness control adjusts the black
levels in the image. The level should be adjusted so
that the color black is achieved (not gray) yet faint
details should still be observable in the shadows. It is
best to use a test pattern known as a PLUGE to set
the levels.
8) Contrast – This control adjusts the level of white in the
image. Using a well-lit image, adjust the contrast for the
brightest image but not so bright that white areas start
to turn green or cause blooming. Blooming is seen as
bright areas of the picture smearing off to the right. It is
best to use a test pattern known as PLUGE to set the
levels.
9) Color – This control adjusts the amount of color in the
image. Adjust to individual taste. The VP251 has an
AGC (Automatic Gain Control) that adjusts the color
level automatically to maintain optimum color settings,
using the customer’s adjusted setting as a reference. It
is best to use a test pattern known as SMPTE color
bars with a blue filter to properly set the levels.
10) Tint – This control adjusts the color phase seen as
the range from green to magenta. The VP251 has an
APC (Automatic Phase Control) that maintains proper
phase. This setting is best left in the preset position.
It is best to use a test pattern known as SMPTE color
bars with a blue filter, to properly set the levels.

10
VIDEO PROCESSOR OPERATING INSTRUCTIONS
The adjustment levels can also be seen on the projec-
tion screen for easy adjustment.
ZZ
Contrast
Step 1
Press Control Step 2
Adjust Level
Figure 4
DETAIL CONTROLS
The VP251 offers an advanced Detail circuit. The cotrol
works provides optimum picture detail without introducing
“ringing” artifacts for both horizontal and vertical edges.
This is very helpful with low quality sources such as VHS
tapes. Also, even high quality sources such as DVDs and
Laserdiscs can have excessive detail enhancement
recorded in the movie this can be seen as white halos
along dark edges. The detail controls can be reduced, to
limit the visibility of the halos.
However, for the most part, the settings should be left in
the preset setting. If the detail level must be turned way up
to see details, there is a good chance there are other fac-
tors involved, such as the projector becoming out of focus
PICTURE CONTROLS
The front panel offers complete controls of key picture
adjustment parameters; Brightness, Contrast, Tint, Color
and Detail.
To adjust the different controls simply press the button
associated with the parameter to be adjusted and toggle
the value key up or down (see Figure 4). The LCD readout
on the front panel provides a status report with both num-
bers and a bar graph for setting levels.
Presets – Once the levels have been adjusted for the best
image they can be stored as one of four presets. There
are four present for each input source, i.e. four for Video,
four for S-Video, etc.
To store, first adjust the image then press the Store button.
The next preset button pushed, will store those settings.
The preset will automatically be recalled the next time that
input is selected.
The Factory Preset button recalls all settings to SMPTE
reference standards. When aligning the projector for the
first time, the VP251 should be in the factory preset. Using
an external test pattern from a DVD, laserdisc or pattern
generator, adjust the brightness and contrast using the
projector’s controls. Then adjust Color, Tint, and Detail
using the controls on the VP251. Once completed, store
the settings in one of the presets.
To store presets using the On-Screen-Display (OSD) with
the infrared remote, first adjust the setting for the best
image possible, then use the Function key to scroll down
to the Store function. Use the Value key to select which
preset to store the information. The information will be
stored either when the Function button is touched again
or when the OSD times off (after approx. 10 seconds).
Select the different presets by pressing the Preset button
on the remote.
OSD Off – The OSD can be turned on and off by
pressing the Factory button and the Preset 1 button
at the same time.
11) Detail – This control adjusts the amount of large
and small edge details. The level should be set
where there is the maximum amount of edge detail
without excessive “ringing” and harshness. For
most sources, this should be left in the preset set-
ting.
12) Store – Press this button to activate the store func-
tion. The next preset pressed will store the current
settings.
13) Factory – The Factory Presets are set to broadcast
industry standards. And can be used as a reference
or to reset levels if they get misaligned.
14) Presets – This control stores all picture adjustments
in a nonvolatile memory. There is a separate bank of
four presets for each input, that are automatically
recalled when the input is selected.
15) Value Adjust – This rocker switch adjusts the value
of each function. Pressing the top portion increases
the level, pressing the bottom portion reduces the
level.
16) IR Window – Receives the information from the
remote control. Do not block this sensor.

11
Many of the new generation of projectors and computer monitors require TTL sync levels to operate correct-
ly. The D15 output on the Faroudja processors output TTL sync. The best approach in these circumstances
is to use a standard D15 to RGB breakout cable and connect it to the D15 connection on the Faroudja
processor. Use the H & V sync from the breakout cable and the R, G, B from the BNC connectors on the
rear panel for the best image.
Problem Solution
No power light Unit not turned on
Unit not plugged in
Fuse blown
No power at plug
No picture Video source not selected
No video source connected or operating
Projector/Monitor not turned on
Projector/Monitor not connected correctly
Bad video cable
Unit in freeze mode
Check brightness and contrast levels
Colors bleeding Check termination
Check projector/monitor termination
Contrast set too high
Color set too high
Picture not stable Check interface cables
Sync cables are swapped or not connected
Input source not selected correctly
Check input terminations
Projector Fast/Slow Horizontal time constant. Should be set to fast.
Incorrect colors Tint in manual mode
Defective output cable
RGB cables are swapped
Check projector/monitor termination
Input source not selected correctly
No burst on input
RGB or Y,R-Y, B-Y Inputs not terminated.
Picture washed out Composite input not terminated
NOTE: To make sure that an input source is not the cause of a problem for a composite source, turn the
termination switch off and connect a composite monitor to the composite input Loop input.
To make sure that a projector is not the cause of a problem, connect a 31.5KHz multisync monitor to the
15pin output connector and check the display to see if it is correct or if the monitor display shows the same
problem as the projector display, then the VP251 has a problem and you should contact our Technical
Support Department.
TROUBLESHOOTING

12
APPENDIX A
RS-232 PROGRAMMING INSTRUCTIONS
The VP251 can communicate with other controllers
that provide an RS-232 interface. Adjustable baud
rates are 19,200, 9,600, 4,800, 2,400 and 1,200
with 9,600 as factory default. (Contact factory for
details if baud rate needs to be changed.)
Communication settings are 8 bits, N parity and 1
stop bit. A terminal emulator program, like the one
found in Windows, can be used to control the
VP251.
All RS-232 commands require the header of
‘VP251’ to be used at the beginning of each new
command string, followed by any of the commands
listed below. Commands may be of either upper or
lower case characters. All commands are
terminated by a carriage return (13H).
RS-232 Commands:
The following commands can be listed a a multiple
command separated by a comma:
B = Brightness ( 0 to 255 )
C = Contrast ( 0 to 255 )
K = Color ( 0 to 255 )
T = Tint (0 to 255)
D = Detail (0 to 15)
Example: VP251,B100,C75 (ENTER)
2
3
5
2
3
5
RxD
TxD
Ground*
TxD
RxD
Ground*
PC Computer
9 Pin Male “D” VP251 9 Pin Female “D”
*2 Conductor Shielded Wire Recommended
VP251 RS-232 Cable
The following commands must be entered individually:
HELP = Displays a help menu
P0 = Factory Preset ( not user changeable)
P1 = User Preset 1
P2 = User Preset 2
P3 = User Preset 3
P4 = User Preset 4
L1 = Store User Preset 1
L2 = Store User Preset 2
L3 = Store User Preset 3
L4 = Store User Preset 4
ON = Turn On the VP251
OFF = Turn Off the VP251
ST = Return current settings status to controller
V = Select Video Input Mode
Y = Select Y/C Input Mode
X = Select YUV Input Mode
R = Select RGB Input Mode
G = Select VGA Input (Computer/HDTV pass-through)
E0 = Echo Off
E1 = Echo On (default)
The On-Screen-Display (OSD) location on the monitor
can be changed using RS232 commands. The OSD
can also be disabled by RS232.
OSD ON = Enable the OSD
OSD OFF = Disable the OSD
OSD xxx,xxx = (Where xxx = 0 to 152) Select
placement of OSD (factory default: 0,35)
OSD can also be changed by moving a jumper located
inside the unit. Contact factory for details.

13
APPENDIX A
VP251:B###,C###,K###,T###,N###,D###,V,T1,A1,F0
(Y)
(R) Freeze
(X) Digital Filter
Auto-Tint
Input Select
Detail Level
Noise Level
Tint Level
Color Level
Contrast Level
Brightness Level
Header
ST or st This command will return a string
showing the current settings of the
VP251. Example:
HELP or help This command will return a
list of commands used for
the VP251Line Multiplier.
VP251 Local / Remote Operation
The unit stores all of it’s settings in a non-volatile
ram and will return to the last known settings when
the unit is power up. The only exception is the
Freeze function. The Freeze function will be set off
during the power up cycle.
When a command is received via the RS-232, only
those functions are placed in the remote mode. If a
function is set via the remote, it can be returned
back to local mode by adjusting that function on
the front panel. This is accomplished by creating a
window around that function when in remote
mode. If that function is turned beyond the window
setpoint, that function is returned to local mode
and becomes active again.
Command String Examples:
Commands can be as simple as:
VP251,B150(CR)
to complex as
VP251,D240,N20,C150,B102,V,T0,A1,F0(CR)
Note (CR) = Carriage Return (OxOd) or ASCII 13

14
APPENDIX A
VGA Connector and Component Video con-
nector Pinout
Pin Function
1 Red Video
2 Green Video
3 Blue Video
4 Not Used
5 Ground
6 Red Return (Ground)
7 Green Return (Ground)
8 Blue Return (Ground)
9 Composite Sync
10 Composite Sync Return (Ground)
11 Not Used
12 Not Used
13 Horizontal Sync
14 Vertical Sync
15 Not Used
Cable Lengths and Distribution Amplifiers
To achieve the best results from your installation,
we suggest the following minimum standards for
cable runs when a VP251 is used.
To preserve the video quality of the VP251, the
signal path should be no more than –3db down at
25 MHz through a 75 ohm cable. Any distribution
amplifier should have a bandwidth no less than
–3db down at 25 MHz.
The following cable lengths are the maximum rec-
ommended continuous lengths of 75 ohm coax
cable and 15 pin VGA cable (when using the VGA
output).
Cable Type Maximum Length
Mini BNC cables, 75 ohm 100 Feet
1.15nS/Foot propagation
RG-59/U type cable, 75 ohm 150 Feet
75 ohm precision video cable 200 Feet
Belden 8281
15 pin, high resolution VGA cables 25 Feet
utilizing individual high resolution
mini-coax cables for each signal from
VP251 to monitor.

15
SPECIFICATIONS
Design and specifications are subject to change without notice.
INPUT SIGNALS (NTSC) 525 Line 2:1 Interlace
Video 1Vp-p, Negative Sync, 714mV Luminance
S-Video Y/C (3.58) Non-Composite, 700m/Vp-p Y, 286mVp-p C
(Burst)
RGB 700mVp-p Non-Composite, 1Vp-p Composite
YUV Y(1V w/Sync), R-Y(714mV), B-Y(714mV)
INPUT SIGNALS (PAL) 15 pin ‘D’ Connector, Computer or HDTV
625 Line 2:1 Interlace
Video 1Vp-p, Negative Sync, 700mV Luminance
Y/C Y/C (4.43) Non-Composite, 700m/Vp-p Y, 286mVp-p C
(Burst)
RGB 700mVp-p Non-Composite, 1Vp-p Composite
YUV Y(1V w/Sync), U(700mV), V(700mV)
OUTPUT SIGNALS (NTSC) 525 Line Progressive Scan/1050 Line per Frame
R, G, B Non-composite, Positive, 714mVp-p
Vertical Sync 59.94Hz, Negative, 4Vp-p, 75 Ohm
Horizontal Sync 31.5KHz, Negative, 4Vp-p, 75 Ohm
Composite Sync 31.5KHz/59.94Hz, Negative, 4Vp-p, 75 Ohm
Output: VGA: RGB 0.700mV Pk-Pk @ 75 Ohms
(Line Doubler Mode) Horizontal Sync, BNC, 31.4 Khz, TTL @ 2K Ohms
Vertical Sync, BNC, 59.94Hz, TTL @ 2K Ohms
Composite Sync, BNC, 31.4 Khz H, 59.94Hz V,
TTL @ 2K Ohms
D-15 VGA Standard
Note: The scan frequencies are not modified when using
the D-15 input loop.
OUTPUT SIGNALS (PAL) 625 Line Progressive Scan/1250 Line per Frame
R, G, B Non-composite, Positive, 700mVp-p
Vertical Sync 50Hz, Negative, 4Vp-p, 75 Ohm
Horizontal Sync 31.25KHz, Negative, 4Vp-p, 75 Ohm
Composite Sync 31.2KHz/50Hz, Negative, 4Vp-p, 75 Ohm
POWER INPUT: 100-240 VAC, 50/60Hz, 35 Watts (Auto ranging)
DIMENSIONS: 3.5” H x 17.00” W x 16.50” D
66.675mm H x 431.8mm W x 419.1mm D
WEIGHT: 17 LBS, 6.34 Kg

WARRANTYINFORMATION
All FAROUDJA Laboratories products are warranteed to the original purchase
against defective materials and workmanship under normal use and service for a
period of one (1) year from the date of shipment. This warranty shall be of no force
and effects if modifications have been made by the purchaser or its agents or
employees or if damage results from connecting the product to incompatible equip-
ment or power. This warranty will also be void if the product is not returned to
FAROUDJA Laboratories in the original shipping container.
The purchaser’s sole remedy with respect to the breach of this warranty is for the
selling distributor to repair or replace, at its option, those products which the selling
distributor determines to have breached this warranty within the specified period.
Any claims under this warranty should be made by telephone or in writing to the sell-
ing distributor or FAROUDJA Laboratories. No products should be returned to the
selling distributor or to FAROUDJA Laboratories without its prior consent, and then,
only with freight prepaid. FAROUDJA Laboratories will prepay the return shipment.
Specifications and price change privileges are reserved.
THIS WARRANTY IS IN LIEU OF ALL OTHER WARRANTIES EXPRESSED OR
IMPLIED INCLUDING, WITHOUT LIMITATIONS, ANY IMPLIED WARRANTY FOR
MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE.
FAROUDJA Laboratories
750 Palomar Ave., Sunnyvale, California 94086
Tel: [phone] Fax: [phone]