Cosmed Pony graphic User manual

SERVICE MANUAL
Pony
PonyPony
Pony graphic
Corporate Office:
COSMED Srl
PO Box n °3, Pavona di Albano RM,
00040 -Italy
Tel:[phone]
Fax:[phone]
email:[e-mail]
North American Office:
COSMED USA,Inc.
2758 North Paulina Street,
Chicago,IL 60614 USA
Phone:[phone]
Fax:[phone]
email:[e-mail]
P/N. C01414-01-91 / Date of Issue: January 2002.

No part of this manual may be reproduced or transmitted in any form without the express
permission of COSMED srl. COSMED does not assume the liability for mistakes in this
documentation or for casual or consequential damages in connection with the provision,
representation or use of this documentation.
This manual has been compiled by means of Adobe Page Maker 6.5 , Microsoft Word, Corel
Draw and CAD programs.
COSMED Software can be installed only in one device.
Word and Excel are registered trade marks of Microsoft Corporation.
DBIII is a registered trade mark of Bordland International Inc.
Lotus 123 is a registered trade mark of Lotus Development Corporation.
Page Maker is a registered trade mark of Adobe Corporation.
Corel Draw! is a registered trade mark of Corel Corporation
Pony graphic service Manual
October 2001 II Edition
Copyright © 1998 COSMED
COSMED Srl - Italy
Part No. C01414-01-91 Rev A.

WARNING
Do not use the equipment in presence of flammable gases or
anesthetic mixtures.
Perform the service procedures described in this manual only if you
are a trained and authorized COSMED service person.
Keep the equipment away from heat, flames, sparks, flammable
liquid mixtures and explosive gases.
For using this equipment along with other medical ones, contact
COSMED.
The following symbols are used into the equipment, in accordance
of the actual standards:
Type B equipment (according to EN60601-1)
DANGER: high temperature
OFF
ON
Protective earth
AC

WARNING
Perform the service procedures described in this manual only if you
are a trained and authorized COSMED service person. You must
have a through knowledge and experience with medical electronic
equipment.
Pay attention to the directions in this service manual, along with the
warning and cautions that appear throughout this manual.
Read through each step in every procedure before beginning the
repair. Always use the proper tools, test equipment and the most
recent revision of this service manual.
Warning
If you deviate from the instructions and/or recommendations in this
manual, you may cause the Pony Graphic to operate improperly or
unsafely, and you may damage the Pony Graphic itself.
The Pony Graphic User's Manual is an integral companion to this
manual. Familiarize yourself with it before operating and repairing
the device.

Service Manual Ponygraphic Table of Contents
i
Table Of Contents
1. Introduction..........................................................................................1.2
1.1. Organisation of the manual .........................................................................................1.2
1.2. Reference Documents..................................................................................................1.2
1.3. Customer Communication...........................................................................................1.2
1.4. Technical Specifications..............................................................................................1.3
1.4.1. Pony graphic Unit ....................................................................................................1.3
1.4.2. Flow meter...............................................................................................................1.3
1.4.3. Power supply:..........................................................................................................1.3
1.4.4. Battery charger........................................................................................................1.3
1.4.5. Windows PC Software.............................................................................................1.3
1.4.6. PC configuration required........................................................................................1.3
1.4.7. Safety and conformity..............................................................................................1.3
2. Functional description ........................................................................2.2
2.1. General Overview..........................................................................................................2.2
2.1.1. Pony graphic Unit ....................................................................................................2.2
2.1.2. Flowmeter................................................................................................................2.2
2.1.3. Battery Charger (AC /DC Adapter)..........................................................................2.2
2.1.4. RS232 cable............................................................................................................2.2
3. Part Description...................................................................................3.2
3.1. Pony graphic Unit.........................................................................................................3.3
3.2. Mother Board (C01350-01-15)......................................................................................3.3
3.2.1. Function...................................................................................................................3.3
3.2.2. Description...............................................................................................................3.3
3.2.3. Adjustments & checks .............................................................................................3.4
3.2.4. Assembly Drawing...................................................................................................3.4
3.2.5. Warnings & Indications in Event of Failure..............................................................3.4
3.3. Display Assembly (C01344-01-30)...............................................................................3.5
3.3.1. Function...................................................................................................................3.5
3.3.2. Description...............................................................................................................3.5
3.3.3. Adjustments & checks .............................................................................................3.5
3.3.4. Assembly Drawing...................................................................................................3.5
3.3.5. Warnings & Indications in Event of Failure..............................................................3.5
3.4. Keyboard Assembly (C01352-01-15)...........................................................................3.5
3.4.1. Function...................................................................................................................3.5
3.4.2. Description...............................................................................................................3.5
3.4.3. Adjustments & Checks ............................................................................................3.5
3.4.4. Assembly Drawing...................................................................................................3.6
3.4.5. Warnings & Indications in Event of Failure..............................................................3.6
3.5. Printer (C01386-01-08)..................................................................................................3.6
3.5.1. Function...................................................................................................................3.6
3.5.2. Description...............................................................................................................3.6
3.5.3. Adjustment & checks...............................................................................................3.6
3.5.4. Assembly Drawing...................................................................................................3.7
3.5.5. Warnings & Indications in Event of Failure..............................................................3.7

Service Manual Ponygraphic Table of Contents
ii
3.6. Opto Electronic Assembly(C00095-01-05) .................................................................3.7
3.6.1. Function...................................................................................................................3.7
3.6.2. Description...............................................................................................................3.7
3.6.3. Adjustment & checks...............................................................................................3.8
3.6.4. Assembly Drawing (Refer to Section: Schematics & Layouts)................................3.8
3.6.5. Warnings & Indications in Event of Failure..............................................................3.8
3.7. Battery Charger (C00766-01-30) (C00767-01-30)........................................................3.8
3.7.1. Function...................................................................................................................3.8
3.7.2. Description...............................................................................................................3.8
3.7.3. Adjustments & checks .............................................................................................3.8
3.7.4. Assembly Drawing...................................................................................................3.8
3.7.5. Warnings & Indications in Event of Failure..............................................................3.9
4. UNIT MAINTENANCE AND CONSUMABLE REPLACEMENT ...........4.2
4.1. Operator Maintenance Program..................................................................................4.2
4.2. Replacement Schedule ................................................................................................4.2
4.3. Preventive Maintenance...............................................................................................4.4
4.3.1. Necessary tools.......................................................................................................4.4
4.3.2. Charger cable A381-003-202:..........................................................................4.4
4.3.3. RS232 serial cable C00032-01-12: ...................................................................4.4
4.3.4. Turbine C00292-01-05: ....................................................................................4.4
4.3.5. Optoelectronic reader C00095-01-05:...............................................................4.4
4.3.6. Pony graphic unit.....................................................................................................4.4
5. TROUBLESHOOTING ..........................................................................5.2
5.1. Careless mistakes during the use of the system ......................................................5.3
5.1.1. Warning ...................................................................................................................5.3
5.1.2. Tools........................................................................................................................5.3
5.1.3. The system doesn't operate when switched on; .....................................................5.3
5.1.4. The printer doesn't work properly;...........................................................................5.4
5.1.5. The Pony graphic is unable to measure properly flow and volume;........................5.4
5.1.6. The Optoelectronic transducer doesn't work;..........................................................5.4
5.1.7. The batteries cannot be recharged or the green led remains off;...........................5.4
5.1.8. Serial Communication error.....................................................................................5.5
5.1.9. The keyboard doesn't work .....................................................................................5.5
5.1.10. The LCD Display back-light doesn't work............................................................5.5
6. Service Procedures.............................................................................6.2
6.1. Consumable Replacement...........................................................................................6.2
6.1.1. Disassembling the Pony graphic.............................................................................6.2
6.1.2. Replacing the internal Rechargeable batteries .......................................................6.3
6.2. Electronics.....................................................................................................................6.3
6.2.1. Display contrast Adjustment....................................................................................6.3
6.2.2. Flow measurement Check and Calibration .............................................................6.4
6.3. Auto Test Mode.............................................................................................................6.4
6.3.1. Running the Auto-test program ...............................................................................6.4
6.3.2. Operating the interactive Diagnosis Program..........................................................6.5
6.4. Connecting to External Printer....................................................................................6.5
6.4.1. External printer: features and connections..............................................................6.5
6.4.2. Main features of the test report................................................................................6.5
6.4.3. Configuration of the printer......................................................................................6.6

Service Manual Ponygraphic Table of Contents
iii
6.4.4. Configuration of the Pony Graphic ..........................................................................6.6
7. SCHEMATICS AND LAYOUTS............................................................7.2
7.1.1. Motherboard (C01350-01-15)...............................................................................7.2
7.1.2. Display (C01344-01-30) .......................................................................................7.2
7.1.3. Key board PCB (C01352-01-15) ..........................................................................7.2
7.1.4. Printer (C00551-01-08)........................................................................................7.2
7.1.5. Optoelectronic Reader (C00095-01-05).................................................................7.2
7.1.6. Optoelectronic PCB (C00609-01-15) ....................................................................7.2
7.1.7. Adapter Plug for Car charging (C00297-01-12) ......................................................7.2
7.1.8. Serial Cable (C00032-01-12)................................................................................7.2
8. Appendix A: Replaceable Part List ....................................................8.2

Service Manual Pony Graphic Chapter 1 Introduction
1.1
1. Introduction..........................................................................................1.2
1.1. Organisation of the manual .........................................................................................1.2
1.2. Reference Documents..................................................................................................1.2
1.3. Customer Communication...........................................................................................1.2
1.4. Technical Specifications..............................................................................................1.3
1.4.1. Pony graphic Unit ....................................................................................................1.3
1.4.2. Flow meter...............................................................................................................1.3
1.4.3. Power supply:..........................................................................................................1.3
1.4.4. Battery charger........................................................................................................1.3
1.4.5. Windows PC Software.............................................................................................1.3
1.4.6. PC configuration required........................................................................................1.3
1.4.7. Safety and conformity..............................................................................................1.3

Service Manual Pony Graphic Chapter 1 Introduction
1.2
1. Introduction
This manual provides the basic procedures for the maintenance and the technical support of
the Pony Graphic. Perform the service procedures described in this manual only if you are a
trained and authorized COSMED service person. You must have a through knowledge and
experience with medical electronic equipment.
Pay attention to the directions in this service manual, along with the warning and cautions that
appear throughout this manual.
Read through each step in every procedure before beginning the repair. Always use the proper
tools, test equipment and the most recent revision of this service manual.
The Pony Graphic User’s Manual is an integral companion to this manual. Familiarize yourself
with it before operating and repairing the equipment.
1.1. Organisation of the manual
This manual is organized as follows:
Functional Description
Provides a general description of the device, the theory of operation and the main usage
modes. This chapter is useful to use the device in the most complete and proper mode.
Part Description:
Provides a detailed description of the device and the theory of operation of the modules. This
chapter is useful to identify cause for problems and to operate properly.
Maintenance
Provides general specifications for maintenance and calibration.
Trouble-shooting
Trouble-shooting guidelines for detecting problems and their respective solutions
Service Procedures:
Description of the adjustments and checks to carry out for a problem
Schematics & Layouts
A collection for drawing for disassembling of the parts, electric and pneumatic schematics,
mounting planes and PCB Layouts
Appendix A
Technical information, replaceable part list, customer communication.
1.2. Reference Documents
The following document contains information that you may find useful for further reference as
you read this manual:
Pony Graphic: User’s Manual P/N: C00296-02-91.
1.3. Customer Communication
COSMED would like to receive your comments and suggestions on its products and manuals.
We are interested in your application with our products, and we would like to help you if you
have problems with them. To make it easier for you to contact us, this manual contains our
address and a Technical Support Form in the Appendix
Our contact Address
COSMED S.r.l,
Via Dei Piani di Monte Savello, 37, P.O Box 3, Pavona di Albano, ROMA
00040 ITALY.
Voice [phone]
Fax [phone] Internet Web site: http://www.cosmed.it

Service Manual Pony Graphic Chapter 1 Introduction
1.3
1.4. Technical Specifications
1.4.1. Pony graphic Unit
Graphic display Backlight LCD 70x80 mm
Display LCD 2 lines x 16 characters
Printer Graphic,24 char/lin,2,5 lines/s
Keyboard 12 multifunction keys
Serial cable RS 232, bi-directional, 4800 baud
Dimensions
Dimensions 237x127x46 mm
Weight 1.2 kg
1.4.2. Flow meter
Flow meter: Digital bi-directional turbine
Flow range 0.03 -20 l/s
Volume range 10 l
Accuracy F/V ± 3%%or ± 50 ml
Dynamic res at 12 l/s <0.7 cm H2O/l/s
Mouthpieces Ø 31 and 22 mm
1.4.3. Power supply:
Ni-Cd Batteries, 5V, 1.2 AH, Rechargeable.
Battery Autonomy 200 tests including prints out
1.4.4. Battery charger
Power supply 120V - 240 V
1.4.5. Windows PC Software
The PC software, running on Windows™, allows the user to manage data stored in the Pony
graphic Unit or transmitted to PC. Here following a list of the main features available:
• Test data management.
• Viewing data in table and graphic form
• Spirometry (FVC, VC, IVC, MVV).
• Adding parameters and predicted equations trough the "Formula Editor" tool-kit.
• DDE with Microsoft Excel.
• Customizing software environments (colours, printed parameters...).
• on line Help.
1.4.6. PC configuration required
• Pentium 133 MHz. Or higher
• Windows 95, 98, NT.
• 16 MB RAM .
• 3.5 drive.
• VGA, SVGA monitor.
• Serial Port RS 232 available ( two serial ports available in case of Ergometer control)
• Any Mouse and Printer compatible with the MS Windows™ operating system.
• PC confirm to European Directive 89/336 EMC
1.4.7. Safety and conformity
SAFETY
IEC 601-1 (1988)/EN 60 601-1 (1990)
Below is reported the complete classification of the device:
• Class B "internally powered equipment" device
• IP00, ordinary equipment unprotected against water penetration;
• Non sterile device
• Device not suitable in the presence of flammable aesthetics;
• Continuous functioning equipment;

Service Manual Pony Graphic Chapter 1 Introduction
1.4
EMC
The system meets the EMC Directive 89/336
EN 60601-1-2,EN 55011 Class B (emission)
IEC 1000-4-2 (immunity ESD): 4KV CD, 8KV AD
IEC 1000-4-3 (immunity EM): 3 V/m
IEC 1000-4-4 (immunity Bursts): 1 KV
QUALITY ASSURANCE
UNI ISO EN 9001 (Reg 387 Cermet)
MEDICAL DEVICE DIRECTIVE (CE MARK)
MDD 93/42CEE (Notified Body 0476)
Class IIa.

2. Functional description ........................................................................2.2
2.1. General Overview..........................................................................................................2.2
2.1.1. Pony graphic Unit ....................................................................................................2.2
2.1.2. Flowmeter................................................................................................................2.2
2.1.3. Battery Charger (AC /DC Adapter)..........................................................................2.2
2.1.4. RS232 cable............................................................................................................2.2

Service Manual Pony Graphic Chapter 2 Functional Description
2.2
2. Functional description
2.1. General Overview
Pony graphic is a portable spirometer designed for carrying out the typical test of the screening
spirometry: Forced Vital Capacity (Pre and Post), Slow Vital Capacity (Inspiratory and
Expiratory) and Maximum Voluntary Ventilation.
The system is mainly composed of following parts
2.1.1. Pony graphic Unit
It is the core of the system; contains the microcontroller and the electronics necessary to
operate the peripherals and to manage the different measurements. It can be operated either in
stand alone mode using the internal rechargeable NiCd batteries or connected to the AC/DC
adapter. It is connected to the Turbine flowmeter during the measurement. It can be connected
to a PC compatible or an external printer by the RS232 interface for data management and
direct printing.
2.1.2. Flowmeter
It is composed by the turbine and the Optoelectronic transducer; the air passing through the
helical conveyors, makes a spiral motion which causes the rotation of the turbine rotor. The
rolling blade interrupts the infrared light sources beamed by the diodes of the optoelectronic
transducer. Every interruption represents half turn of the rotor, this allows to measure the
number of turn in the time. There is a constant ratio between air passing trough the turbine and
number of turns. This allows to calculate an accurate measurement of volume and flows.
2.1.3. Battery Charger (AC /DC Adapter)
The battery charger (AC /Dc Adapter) can charge NiCd batteries of the Pony graphic unit at the
same time battery pack inside the unit and also supply power to the unit. It can operate at both,
110 or 220V AC inputs. It is also possible to use the charger in car using cigar light adapter
cable supplied with standard accessories.
The battery charge status is indicates by a flashing green Led and completely charged one with
Non Flashing one on the top cover pony unit.
2.1.4. RS232 cable
It allows to download the data of the test to a PC compatible or to print the result with an
external Printer (see the User's Manual for the printer specifications).

3. Part Description...................................................................................3.2
3.1. Pony graphic Unit.........................................................................................................3.3
3.2. Mother Board (C01350-01-15)......................................................................................3.3
3.2.1. Function...................................................................................................................3.3
3.2.2. Description...............................................................................................................3.3
3.2.3. Adjustments & checks .............................................................................................3.4
3.2.4. Assembly Drawing...................................................................................................3.4
3.2.5. Warnings & Indications in Event of Failure..............................................................3.4
3.3. Display Assembly (C01344-01-30)...............................................................................3.5
3.3.1. Function...................................................................................................................3.5
3.3.2. Description...............................................................................................................3.5
3.3.3. Adjustments & checks .............................................................................................3.5
3.3.4. Assembly Drawing...................................................................................................3.5
3.3.5. Warnings & Indications in Event of Failure..............................................................3.5
3.4. Keyboard Assembly (C01352-01-15)...........................................................................3.5
3.4.1. Function...................................................................................................................3.5
3.4.2. Description...............................................................................................................3.5
3.4.3. Adjustments & Checks ............................................................................................3.5
3.4.4. Assembly Drawing...................................................................................................3.6
3.4.5. Warnings & Indications in Event of Failure..............................................................3.6
3.5. Printer (C01386-01-08)..................................................................................................3.6
3.5.1. Function...................................................................................................................3.6
3.5.2. Description...............................................................................................................3.6
3.5.3. Adjustment & checks...............................................................................................3.6
3.5.4. Assembly Drawing...................................................................................................3.7
3.5.5. Warnings & Indications in Event of Failure..............................................................3.7
3.6. Opto Electronic Assembly(C00095-01-05) .................................................................3.7
3.6.1. Function...................................................................................................................3.7
3.6.2. Description...............................................................................................................3.7
3.6.3. Adjustment & checks...............................................................................................3.8
3.6.4. Assembly Drawing (Refer to Section: Schematics & Layouts)................................3.8
3.6.5. Warnings & Indications in Event of Failure..............................................................3.8
3.7. Battery Charger (C00766-01-30) (C00767-01-30)........................................................3.8
3.7.1. Function...................................................................................................................3.8
3.7.2. Description...............................................................................................................3.8
3.7.3. Adjustments & checks .............................................................................................3.8
3.7.4. Assembly Drawing...................................................................................................3.8
3.7.5. Warnings & Indications in Event of Failure..............................................................3.9

Service Manual Ponygraphic Chapter 3 Part Description 3.2
3. Part Description
This section deals with the electronic circuits and their functions; it gives an overview regarding
the general aspect of the PCB assembly, its electronic description and the possible errors and
faults, which can occur due to malfunction in the component from that assembly. It provides the
complete reference for the service personnel for diagnosis. The section consists of the
following.
Pony graphic Unit
1. Mother board Assembly (C01350-01-15)
2. Display Assembly (C01344-01-30)
3. Keyboard Assembly (C01352-01-15)
4. Printer unit Assembly (C01386-01-08)
Opto electronic Reader
5. Opto electronic Assembly (C00095-01-05)
Battery Charger Unit
6. Battery Charger Assembly(220V) (C00766-01-30)
7. Battery Charger Assembly(110V) (C00767-01-30)
The circuit diagrams and PCB Layouts are attached for ready reference

Service Manual Ponygraphic Chapter 3 Part Description 3.3
3.1. Pony graphic Unit
The Pony graphic Unit '96 version (P/N: C00307-0X-04), distributed since May 1996, is made
of 4 different PCBs:
Mother Board P/N: C01350-01-15
Display: P/N: C01344-01-30
Keyboard: P/N: C01352-01-15
Printer: P/N: C01386-01-08
The physical structure of the Pony graphic Unit is described in the following block diagram:
The Unit contains most of the parts constituting the spirometer and can be interfaced to the, the
turbine flow meter and with the User's PC or external printer via the serial cable. AC/DC
adapter powers the unit.
3.2. Mother Board (C01350-01-15)
3.2.1. Function
The Mother Board carries the components shown in the above diagram, all the connection
between them perform the following functions:
• Control of the all peripherals (display, internal printer, keyboard...) through the micro
controller U1 (CDP6805);
• Data Acquisition and amplification of the pulses coming from the opto electronic reader.
• Serial communication management (RS232 unidirectional) and interface level regulation
through U11 (MAX233);
• Battery voltage level detection;
• Battery charging management through U10 (TEA1100) of Power Supply Board PCB.
The mother Board layout is enclosed in the Appendix.
3.2.2. Description
(1) Micro controller (CPU) (U1)
The micro controller U1 (CDP6805E3) used in the Pony graphic is responsible for
Data management through its address bus for control data transfer function in accordance with
the firmware: stored in EPROM U4 (27C512 ,64KB)
(2) Clock
The frequency of the clock signal is controlled by the crystal X1 (4.194.304MHz) ,
Connected between pin 2 and pin 3 of the Real Timer Clock U2 (146818A).
The RTC (146818A) send the squared clock pulses to pin 39 of U1 (CPU) and generates the
interrupt signal necessary to measure the turbine pulses width (pin 19 of 146818A).
(3) I/O control(U9)
The I/O control is carried out within the component FPGA (Field Programmable Gate Array) U9
(Actel A1010B). This IC compensates the Latches, Buffers, Logic Gates for control logic.
(4) Reset
The task of the Reset circuit is to boot the CPU program; when the reset signal (pin 1 of U1)
toggles from Low to High, the CPU executes the bootstrap program.
(5) Power down (U13)
The Power Down circuit protects data stored in RAM in event of power failure. It disable the
RAM access by toggling pin 20 and 22 of the RAM U3 (62256). To logic level High
(6) RAM (U3)
The IC (U3) 62256 is a 32KByte Random Access Memory used for saving the tests data and
for temporary memory during calculations. A dedicated circuit supplies power to the IC even if
the Pony graphic is switched off.

Service Manual Ponygraphic Chapter 3 Part Description 3.4
(7) RS232
The serial communication is completely managed by the CPU; the only external component is
U11 (MAX233) which does the voltage level conversion from TTL (0-5V) to RS232 (-12+12V).
The protocol used is the following:
Data bit: 8 Parity: none
Baud rate: 4800 Handshake: DTR Hardware
(8) Power Supply
The power supply to the Pony graphic Unit and the Optoelectronic transducer is done by 4
rechargeable NiCD batteries (1.2V, 1.2Ah).( they are packed in set of 2 ,each set containing
two batteries)
The IC U14 (MAX761) regulates the supply Voltage of the digital components. It also detects
the Low battery status when the battery voltage goes lower than 4.7 Volts.
The IC U12 (MAX635) generates a negative voltage of -18 Volts (pin 11) in order to power the
LCD Display contrast.
The LCD back-light power supply is controlled by software (battery saving mode) and
generated by an switching circuit composed by T1, C32, C33, R33, R34 and Q10; the supply
voltage is about 90 VAC RMS.
The battery voltage directly powers the Optoelectronic Transducer and the Printer.
The IC U10 (TEA1100) performs the battery charging management. The NiCD batteries are
charged with two different levels:
Fast charging: 800mA (front panel green led fix)
Slow charging: 15mA (green led blinking)
The circuit Switches from fast to slow charging when one of the following conditions is verified:
• Battery fully recharged (Voltage Decrement CutOff System; the battery voltage is
continuously monitored by pin 7, when a decrement is detected TEA1100 switch to
slow mode).
• Battery temperature higher than 45°C (the temperature is monitored by thermistor RV2)
• Battery voltage lower than prefixed threshold
• Battery Voltage higher than prefixed threshold
• Charging time higher than 2 hours.
3.2.3. Adjustments & checks
There are no adjustments to be performed on the motherboard.
3.2.4. Assembly Drawing
3.2.5. Warnings & Indications in Event of Failure.
• The system does not operate when switched on (refer to Troubleshooting section)
• Printer / serial communication does not work
RTC
BATTERY
I/O
FPGA
RAM EPROM
U1 micro controller
RS 232
U12 Display control

Service Manual Ponygraphic Chapter 3 Part Description 3.5
3.3. Display Assembly (C01344-01-30)
3.3.1. Function
The display of pony graphic is the main interface for user to enter the patient details , to view
the results and to print a particular test performed by the patient and for all the control functions
to be performed.
3.3.2. Description
The LCD display is CPU controlled by means of the Data Bus (B0-B7) and powered with the
following voltages (see the Display layout in Schematics and Layouts section):
3.3.3. Adjustments & checks
(1) Display contrast adjustment
Adjustment VR Test Point Adjustment Item
VR54 Display Display contrast
It is automatically compensated for temperature variations.
(2) Test Points
Pin 3 of P1 Digital Logic supply (VCC 5V)
Pin 5 of P1 LCD supply (VEE-18V)
Pin 4 of P1 Contrast level VDAJ(-15V)
Pin 1,2 of P1 back-light supply (VEL*90VAC)
3.3.4. Assembly Drawing
3.3.5. Warnings & Indications in Event of Failure.
• Display failure
• Backlight failure
3.4. Keyboard Assembly (C01352-01-15)
3.4.1. Function
The keyboard is the primary input device for the patient data and for executing the test it is
passive device hardwired to the CPU.
3.4.2. Description
The keyboard is directly interfaced with the I/O ports of the CPU by the connector JP7.
Pins 12-13-14 of U1 are outputs while pins 33-34-35-36 Inputs.
3.4.3. Adjustments & Checks
There are no adjustments to be performed on this assembly.

Service Manual Ponygraphic Chapter 3 Part Description 3.6
3.4.4. Assembly Drawing
3.4.5. Warnings & Indications in Event of Failure.
• Key failure
3.5. Printer (C01386-01-08)
3.5.1. Function
The printer used in the Pony graphic is the EPSON M190; it has 8 print solenoids horizontally
placed. Each solenoid moves from left to right in order to print 18 dots so the total number of
dots/line is 144.
3.5.2. Description
The following schematic shows the control circuitry for the printer.
The Printer motor is activated and stopped by the two signals M_ON (Motor On) and M_OFF
(Motor Off).The signal Fast Line Feed controls the paper feed and it is directly operated by the
CPU (pin 30).The feedback signals coming from the Printer are monitored in order to detect the
exact position of the solenoids.
The supply voltage comes directly from the Batteries and the peaks of the current can reach
10A.
3.5.3. Adjustment & checks
There is no adjustment on this assembly.