Pentax EPK-i User manual

SERVICE MANUAL
(Version 03)
High-end Video Processor
PENTAX EPK-i
Medical Instrument Division / Service Technical Group
MNL-045-03 / May 16, 2008

< CONTENTS>
1. Specifications Page 1
2. General explanations Page 2
Feature
3. Functions Page 3
4. Configuration (Main parts) Page 6
5. Precaution Page 7
6. Service Page 8
6.1 Lamp block
6.2 Pump Page 10
6.3 Iris Page 13
6.4 Peripheral Board (G700) Page 14
6.5 Process Board (H700) Page 15
7. Electrical safety test Page 18
7.1 Dielectric strength test
7.2 Protective GNDing wire resistance
7.3 Leakage current test Page 19
8. Trouble shooting Page 20
9. Wiring Diagram Page 21
Appendix –Exploded view
Parts list
Notes for using this Service Manual
1) Up-date of Service Manual will be notified by such information as Notice of Modification,
Service Note and so on.
2) When you start repair servicing, be sure to leave service records.
3) This Service Manual voids preceding "New Product Repair Guide" for the same model, if any.
4) Upon request, PENTAX will provide qualified service personnel with further information to
service this product provided that the requested information needed within the range of
servicing described in this Service manual.

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1. Specifications Specification
Item Description 120V model 230V model
Video system NTSC PAL
Voltage 120VAC 230VAC
Frequency 50 - 60Hz
Power consumption Less than 5.4A Less than 2.8A
Power requirement
Voltage fluctuation +/-10%
Temperature 10 –40 ℃
Relative humidity 30 –85 %
Operation environment Atmospheric pressure 700 –1060 hPa
Temperature -20 –60 ℃
Relative humidity 0 –95 %
Storage environment Atmospheric pressure 700 –1060 hPa
Lamp 300W Xenon lamp
Lamp average life span Continuous use,Average 500 hours
Color temperature 6,000K
Iris control Automatic / Manual
Brightness control Adjustable by +/- 5 steps each
Illumination
Auxiliary lamp 3W White LED (IEC60825-1)
Scope compatibility PENTAX Color Video Endoscope i-series and K-series
(K-series with Y/C output)
Color correction Red and Blue each adjustable by +/- 5 steps each
White balance Adjustable automatically with “White Bal”button
DVI-D, DVI-A DVI x 1 terminal (either DVI-D or DVI-A is assigned)
RGBS output 9pin D-sub x 2
Y/C output S terminal x 2
Composite video output BNC connecter x 1
DV output DV terminal x 1
Printer output N. A. 9pin D-subx1,
Sterminal x1
Video signal
Analog input BNC connector x1 Sterminal x1,
BNC connector x1
Serial output USB A terminal (Female) x 2 (for memory, printer)
Digital output LAN RJ45 terminal x 1
Audio input Analog input Stereo mini plug x 1
RS-232c 9pin D-sub x 1
Remote Stereo mini plug x 3
Keyboard 6-pin Mini-DIN x1 (exclusive or ordinary PC keyboard)
Footswitch 4pin Bayonet lock type(Female) x 1
Water feeder (SA-P2) 4pin Bayonet lock type(Female) x 1
Control signal
Sync signal (Y signal) BNC connector x 1
Control
On / Off, Air flow volumes are selectable in 5 steps
Level 1: 2.0 –2.8 L/min.
Level 2: 2.9 –3.4 L/min.
Level 3: 3.5. –4.0 L/min.
Level 4: 4.1 –4.5 L/min.
Level 5: 4.6 –7.2 L/min.
Air feeding
Air pressure 45 –70 KPa
Display 6.4 inch TFT
LCD touch screen Touch screen Pressure-sensitive type
Electric shock protection Class –I
Degree of protection BF type
Classification electro
medical equipment Degree of explosion
proofing Do not use in potentially flammable surroundings.
Electromagnetic
Interference Electromagnetic compatibility Complied with IEC60601-1-2 Class B
Harmonic current
emissions Complied with IEC60601-3-2 Class A
Medical electrical
equipment general
requirement for safety
UL60601-1 IEC60601-1
Size Dimensions 430mm (W) x 485mm (D) x 205mm (H)
Weight Main body 26.5Kg
Table-1 Specifications
Photo
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1 New label

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2. General explanations
The PENTAX EPK-i is a high-end Video Processor, which produces High Definition images with a
specially developed scope “Mega Scope 90i”. Several image processing methods (advanced
enhancement, etc.) that help the user observe precisely and easily have been introduced. At the same
time, the EPK-ikeeps compatibilities with the former K-series scopes (Y/C signal type). To obtain stiller
frozen images, a mechanical structure (rotary shutter etc,) has been built in. A user-friendly manner has
been established with several new devices.
Features
1) High Definition image> High Definition images can be created with “Mega Scope 90i”which has a
mega pixel CCD. The 90i scope provides the image data in digital signal to the EPK-i. The EPK-i
can process the image signal without converting the analog signal. The EPK-i has a DVI (Digital
Visual Interface) output port. Therefore non deteriorated image can be seen on the PENTAX LCD
monitor (when “DVI-D”port of the monitor is used. / For analog signal, “VGA”port is also available
on the monitor). The DVI port can provide either DVI (digital signal) or VGA (analog signal)
depending on “DVI Output”setting of the system (refer to the Owner’s Manual). The default setting
is “VGA”. When the full digital environment is used, “DVI Output”must be set to “DVI”. Otherwise
the image will not appear on the monitor.
Note: PENTAX LCD monitor will be launched soon.
Asummery for the monitor connector, exclusive cable and “DVI Output”setting are shown in the
table below:
Connector on LCD monitor
Connector of cable DVI Output setting
DVI-D
DVI
VGA
VGA
Note: The connectors shown in the table are male.
Because DVI signal is very fast, the DVI cable is limited to 3m. With a longer cable, the image
becomes noisy as opposed to the image on the analog CRT monitor becoming darker with an
analog longer cable.
2) Advanced Enhancement>In addition to the ordinary image enhancement (Edge enhancement),
Surface Enhancement and Contrast Enhancement are available. Both enhancement modes cannot
be used simultaneously. The other one will be disabled.
3) Still and Fine Freeze> Thanks for the progressive scan method on the mega pixel CCD and the
rotary shutter of the EPK-i, stiller and finer images can be captured. Because of the progressive
scanning the captured image is real as opposed to the compensated or interpolated image from the
field scanning. The finer image is attributed to the progressive scanning. Meanwhile the rotary
shutter controls the exposure time. The shorter the exposure time is, the stiller the frozen image
becomes. However as the side effect the image becomes darker. Together with the ordinary iris, the
rotary shutter controls the exposure time as short as possible and so that the luminance becomes
enough for the acceptably brighter and stiller image. During the progressive scan, the next light
comes through the hole of the rotary shutter. Thus another mechanical shutter interrupts the light.
This shutter is driven by a solenoid motor and momentarily closes. As a result of the stiller freeze,
mechanical parts are increased. However no adjustment or it is easy if any.
4) LCD Touch panel>As an operational panel, an LCD touch screen panel has been introduced. The
EPK-i has a single board computer inside. Thus it takes about one and half minutes by the LCD
touch panel is ready for the operation. The LCD touch panel reacts by pressure, which is a sensitive
device. Do not operate it with a sharp edge. The lamp, pump and white balance switches are
independent from the single board computer. It means the lamp can be turned on and the pump
works with level-1 before the system has been up and running. The LCD touch screen has a
function that an image put from “VIDEO IN”port is displayed.
5) SA-P2 port>The exclusive port for the water jet supplier SA-P2 is available on the back panel of
the EPK-i. When the scope button or the foot switch assigned with function “WJ”is pressed, an
open-collector, active-low signal is sent to the SA-P2 to turn on and off.
6) Lamp>The lamp (300W xenon lamp) can be replaced by a lamp cartridge (OL-X25) by the user
(refer to the Owner’s Manual). The door of the lamp house can be opened without any special tool.
This door activates the interlock switch for AC power of the unit when it is completely closed. The
lamp cartridge consists of the lamp, two heat sinks and IR cut filter. Trained service engineers are
allowed to replace the lamp itself (The Service manual for the EPK-i will be issued soon. Please
refer to it in detail).

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7) Pump>Air feed volume can be changed in five levels with the touch screen panel. The air feed
volumes of each level are set with the special Set up menu (It is a hidden menu to customers).
When the peripheral board (G700) is replaced for the pump function repair, the former setting value
can be reused without measuring the air feed volume with an air flow meter. When the pump is
replaced, the air feed volumes of each level will be adjusted with the menu by measuring the air
feed volume with the air flow meter. The peripheral board is attached with a small tube from the
pump. It has been prepared for the precise air feed control, however it is not currently working. But
if it is detached, the air must leak at this point. As a result, the air won’t be fed from the air outlet.
8) Auxiliary lamp>3W while light LED has been introduced as an auxiliary lamp. When the main lamp
ignition failure continues for about 8 seconds, the auxiliary lamp automatically comes into the light
axis by the solenoid motor.
9) DC Power supply for patient circuit>The DC power supply unit for the patient circuit exists
independently from the DC power supply unit for the secondary circuits. However the input of the
DC power supply unit for the patient circuit is connected to the DC output of the DC power supply
unit for the secondary circuits. The reason why the DC power supply units individually exist is just
due to limited spaces of the EPK-i unit inside.
10) Lamp power supply unit>The main unit and the igniter exist individually. Of course they are
connected each other. However they can be treated as a spare part independently.
11) Scope detector>A limit switch has been attached just beside the scope connector assembly. When
the scope handle is turned clockwise to lock the scope connector, the switch is activated and the
system recognizes that the scope has been connected completely.
12) Processor ID>The processor model name “EPK-i”and its serial number have been stored as ID.
These information must be necessary for the LAN environment.
13) Serial and LAN port>Using an USB memory device or LAN, system modification can be done
easily.
14) XLUM and Manual mode>Both modes act as an iris manual mode. On the basis of the
concepts that “XLUM”is for confirming the location of the scope distal tip and “Manual”is for
observing the specific parts in vivo in iris manual mode, these modes are available
independently.
3. Functions
1) Preprocess Board (J700)
1)-1 Image signal processing> Because the EPK-i can accept all types of the K-series scopes,
Preprocess board has a function that can process the three kinds of the image signals such as
R-Y/B-Y color differential signal (old 30/40 series), Y/C signal (30/40 or 70/80 series ) and LVDS
signals (90K and 90i series).
R-Y/B-Y and Y/C signals (analog) are converted into 10 bit YUV signal with the video decoder/ADC
(U16).
The 20 bit YUV signal is sent to the FPGA (U23) and converted into 12 bit YCbCr signal.
Finally the 12 bit YCbCr signal is sent to Process board (H700) through the connector CN13 on
Mother board(E700).
As for LVDS signal, DO+/DO- (LVDS: Low Voltage Differential Signal) is sent to the
serializer/deserializer (U42) to be serialized into 12 bit (90i scope) or 8 bit (90K scope) LVDS signal.
The LVDS signal is sent to the also the FPGA (U23) to be converted into 12 bit YCbCr signal.
Finally the 12 bit YCbCr signal is sent to Process board (H700) through the connector (CN13) on
Mother board(E700) as well.
With 90i scope, the white balance is adjusted with the FPGA (U23). With the other scopes, the white
balance is adjusted with the control board in the scope.
1)-2 Iris signal> Depending on a scope, there are three kinds of signals from the scope that is used for
the iris control –“YIRIS”(90K scope), “Yout”(30/40, 70/80K scope) and “DO+/DO-“(90i scope). And
there are two types of processing the iris control signals.
“YIRIS”or “Yout”signal is converted into 12 bit iris control signal with the AD converter (U56).
“DO+/DO-“is converter into 12 bit iris control signal with the FPGA (U23).
Both converted signals are sent to Peripheral board (G700) through the connector (CN13) on
Mother board (E700).
1)-3 Patient circuit> Because Preprocess board that is directly connected to the scope exchanges
signals with the scope, it has digital isolators that divides Preprocess board into the patient circuit
and the ordinary circuit.
2) Process Board (H700)
2)-1 Image signal processing>This board receives 12 bit YCbCr signal from Preprocess board (J700)
through Mother board (E700).

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The 12 bit YCbCr signal is processed by enhancing or changing color with the front panel operation
with the FPGA (U2).
The processed YCbCr image signal is converted in to 10 bit RGB signal with the DSP (U2), and
sent to the FPGA (U39).
The 10 bit RGB signal is sent to Video process board (I700) through the connector (CN8) on Mother
board (E700) after gamma compensation with the FPGA (U39).
Meanwhile the same 10 bit RGB signal is converted into 8 bit RGB signal with the FPGA (U39).
The 8 bit RGB signal is sent to the digital display processor (U51) to be superimposed with
characters.
The 8 bit RGB signal with characters is sent to the two ways. One is to the panel link transmitter
(U56) to be converted into the image signal for DVI. And the image signal for DVI is sent to I/O-1
board (L700) with the internal cable (B521).
The other one is sent to D/A converter (U59) to be converted into RGB analog signal for VGA. And
the RGB analog signal is sent to I/O-1 board (L700) with the internal cable (B522).
The digital display processor (U51) has function to zoom up the image or to make a sub screen.
2)-2 Character generation>The FPGA (U2) handles the keyboard operation.
The FPGA (U2) detects the character inputs and sends the instructions to the digital display
processor (U51) to create the characters.
The digital display processor (U51) generates the characters and merges them to the image signal.
The fixedly displayed texts like “Age”are stored in the memories connected to the FPGA (U2).
These texts are also merged to the image signal with the digital display processor (U51).
The FPGA (U2) also sends the instruction to the digital image processor on Video Board (I700) in
order to create appropriate characters to meet the different display resolution.
3) Video Board (I700)
3)-1 Image signal processing-1>This board receives 10 bit RGB signal from Process board (H700)
through Mother board (E700).
The 10 bit RGB signal is converted into the 8 bit RGB signal and sent to the digital display
processor (U100, 102) to be merged with characters.
The 8 bit RGB with characters is sent to the digital video encoder (U303) through the FPGA (U301)
and encoded into RGB analog signal. Finally the signal is sent to the RGB port x2 on the back panel
through I/O-1 board (L700).
Also the 8 bit RGB with characters is sent to the digital video encoder (U310) through the FPGA
(U301) and encoded into Y/C analog signal. Finally the signal is sent to the Y/C port x2 on the back
panel through I/O-1 board (L700).
The same 8 bit RGB signal with characters is corrected with the FPGA (U301) in order to meet the
required printer color. The look-up-table in the FPGA (301) is used for the color compensation. The
corrected RGB signal is converted into RGB and Y/C analog signal with the digital video encoder
(U317 and U324) and sent to the RGB or Y/C printer port on the back panel through I/O-2 board
(M700). Note: This port is not available with 120V model.
3)-2 Image signal processing-2>This board creates DV format image signal.
The 10 bit RGB signal is converted into the 8 bit RGB signal and sent to the digital display
processor (U100) to be merged with characters.
The 8 bit RGB with characters is sent to the DV encoder (U411) through the FPGA (U301) and
encoded into DV signal. Finally the signal is sent to the DV port on the back panel through I/O-2
board (M700). Audio picked up by the microphone attached to “Audio IN”port on the back panel is
converted into 4 bit digital signal and sent to the DV encoder (U411) to merge to the DV signal.
3)-3 Image signal processing-3>This board receives the outer video signal to superimpose it on the main
image.
Outer video image is accepted from “COMPOSITE-IN”port through I/O-2 board (M700).
The outer video signal is converted into 8 bit rec656 format signal with the video decoder (U208)
and sent to the digital display processor (U100).
The outer video signal is processed as picture-in-picture data with the digital display processor
(U100) and merged to the main image.
4) Peripheral Board (G700)
4)-1 Iris control> With every type of scope, the luminance signal is converted into the 12 bit iris signal on
Preprocess board(J700).
The 12 bit iris signal is sent to the FPGA (U19) to measure if the current iris position is adequate
against the brightness set by the front panel.
The digital signal controller (U12) creates the iris reference signal (analog) by referring to the results
measured with the FPGA (U19). The iris reference signal is sent to the iris analog circuit to control
the iris.

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4)-2 Rotary shutter control> To obtain a stiller frozen image, it is necessary to control an exposure time of
light. It is accomplished by adjusting the hole on Rotary shutter (M4). The parts related to Rotary
shutter consist of Rotary shutter (M4), Space motor (M6), Photo interrupter (PI1) and Shutter (M3).
These are controlled with Peripheral Board (G700).
4)-3 Pump control> The pump control signal (Pump ON-OFF, Air flow level 1-5) are sent from the front
panel to Peripheral Board (G700) through Process Board (H700) to turn the pump ON-OFF.
The pump control signal is sent to the micro controller (U32) to turn the pump ON-OFF.
After the micro controller (U32), a part of the pump control signal is sent to the digital potentiometer
to set the air flow level.
4)-4 Auxiliary lamp control> The lamp power supply unit sends the lamp failure signal to Peripheral Board
(G700) when the lamp ignition fails or the main lamp turns off unexpectedly.
The lamp failure signal from the lamp power supply unit is detected by Peripheral Board (G700) and
sent to the FPGA (U19).
The FPGA (U19) sends signals to Auxiliary lamp to move its LED lamp into the light axis and turn on
the LED lamp.
5) SBC Board (F700 / SBC: Single Board Computer)
5)-1 Touch Panel and LCD Display control> To control the capacitive type touch panel and manage the
various operation buttons and menu tabs.
5)-2 USB Memory control> When the image is captured with the setting that the image output has been
assigned to “SERIAL OUT1, 2”port, the captured image will be sent to the USB memory connected
to the port.
5)-3 Patient Data management> To provide the graphical user interface for the patient data and store the
data.
5)-4 Serial port control> To control the RS-232C port for “ENDONET”database software.
5)-5 LAN control> To control the port for a local area network.

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4. Configuration (Main parts)
Photo-1 EPK-i Main parts
Front panel
Power Switch
Fig-1 Mechanical block
Rotary Shutter
Hole Control Motor (M6)
Iris
Rotary Shutter
Auxiliary Lamp (LD1)
Shutter
Scope
Connector
SBC (F700)
Video Board (I700)
Process Board (H700)
Peripheral Board (G700)
Preprocess Board (J700)
under cover plate
Video Capture
Board (O700)
Touch Panel
LCD Display
Card Cage on
Mother Board (E700)
Covers for Card cage and
Power supply are available
I/O-1 Board (L700)
I/O-2 Board (M700)
I/O-3 Board (N700)
Switching Power Supply (PS1)
Lamp Power Supply (LU1)
Lamp
Igniter (IGN1)
Pump (PU1)
Mechanical Block
Interlock Switch (SW2)
Bypass Board (P700)
DC-DC Converter (PS2)
Pointing blinded parts
Iris Motor (M1)
Auxiliary Lamp Motor (M7)
Shutter Solenoid (M3)
Rotary Shutter
Main Motor (M4)
Light Axis

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5. Precaution - Important
1) General
You have to take utmost care to follow the general rules and practice for safety in servicing electrical
medical equipment.
2) Power off before servicing
For electrical safety, make sure to disconnect the power cable before opening the cover.
3) Route of electrical wire
Be sure to keep the original routes of the electrical wires and the original positions of the cores.
Otherwise it may break the compatibility with the EMC regulation or may cause problems such as
lamp ignition failure. You must put the wires back to the original routes after the maintenance. You
should take photos of the wires and cores beforehand.
4) High temperature on the lamp
Just after turning off the lamp it may be hot. Be careful not to suffer heat injuries when replacing a
lamp.
5) Electrostatic Discharge
To avoid damaging PCBs, wear anti-static protection such as a wristband and discharge the
electrostatic charge before servicing.
6) Disassembling parts
The procedures of disassembling the mechanical and electrical parts are not described in detail in the
service manual. Unless otherwise mentioned, detach from the outer parts to the inner parts or from the
upper parts to the lower parts. In the case a special technique is necessary, it is described. You can
refer to the exploded view pages as well.
7) Electrical safety test
Be sure to do the following tests when you did a repair by opening the cove, after putting back all of
the disassembled parts and the cover to the original position. The procedures are described in
following pages.
a) Dielectric strength test, b) Protective earthing circuit resistance, c) Leakage current test

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Photo-2 Lamp block
Screw x3
Hook
Heat sink
Rear Front
6. Service
Note: Refer to Photo-1 for the location of the parts to be replaced. And also refer to appendix pages for wire routing.
6.1 Lamp block
A way of replacing the lamp bulb and reusing the heat sink is described below.
Important: 1) This job must be done by a person who has got the service training for the EPK-i.
2) The IR cut filter cannot be reused, must be replaced together with the lamp bulb. A spoiled
filter may cause heat injury due to intensive light through the scope.
1) Take out the lamp block from the lamp house.
2) To detach the old lamp, unscrew the three screws and release the hook.
See Photo-2. Remove Front heat sink by rocking it.
Hint: It may be hard to detach Front heat sink and occasionally Filter ring
comes off attaching on the lamp bulb. In this case, put Filter ring back
to Front heat sink.
3) Replace the IR cut filter with a new one in the following order:
a) To remove Spring ring from the ditch in Filter ring, insert the tip of
the thin screw driver into the hole of Filter ring and push the end of
Spring ring toward the center a little bit and lift it by the tip of the screw
driver. See Photo-3 left.
Hint: If the end of Spring ring is not located at the hole of Filter ring, rotate
Spring ring by pressing the other end with a screw driver to be so.
Caution: 1) Do not apply excessive force to Spring ring when detaching it so as not to spoil it.
2) Spring ring may pop out when detaching it. Cover it by a palm.
b) Replace IR cut filter with new one without tainting nor scratching it.
Hint: Confirm if IR cut filter has settled horizontally in Filter ring.
c) Pinch both ends of Spring ring (shown by coloring in red) with two pairs of tweezes and then put
Spring ring into the ditch of Filter ring while narrowing the cut in Spring ring. See Photo-3 Right hand
side.
Hint: The opposite part (shown by coloring in green) against the cut in Spring ring should be put into the ditch of
Filter ring first and the rest of the ring will be put into the ditch subsequently.
Caution: Do not taint nor scratch IR cut filter while attaching Spring ring. If it is tainted, clean it carefully with
isopropyl alcohol solution. If it is scratched, discard it.
d) Confirm if IR cut filter and Spring ring have been attached correctly by waving Front heat sink. If a
click sound can be heard from IR cut filter, it is OK. If not, do it from scratch.
Screw driver
Filter
End of Spring ring
Hole of Filter ring
Front heat sink
Filter ring Spring ring
IR cut filter
Spring ring
Tweezes
Tweezes
Narrow the cut
Photo-3 IR cut filter replacement