Leica M500 N User manual

Service manual Leica M500 N, M520,
M525
10 665 751 – Release 09/2007
Table of contents
1. Technical Description
2. Wiring Diagram and Locations
3. Service Programs
4. Fault Finding
5. Replacing Modules
6. Maintenance Service
7. Inspection
8. Spare Parts

Release 09/2007
• First edition

Service manual Leica M500 N, M520, M525 Description
Doc Code 10 665 751 1-I 08/2007 Gahe
1. Description - Leica M500 N, M520, M525
Table of content
Chapter Page
System description 1-1
General 1-1
Overview control unit 1-1
Overview optics carrier 1-2
Electrical accessories 1-3
Optical/mechanical accessories 1-3
Configuration M525 systems 1-4
Product history M500 N…M525 1-5
Electrical description 1-7
General 1-7
CAN bus 1-8
Optics carrier 1-9
Control unit 1-11
Technical data M525 1-13

Description Service manual M500 N, M520, M525
08/2007 Gahe 1-II Doc Code 10 665 751

Service manual M500 N, M520, M525 Description
Doc Code 10 665 751 1-1 08/2007 Gahe
Description of the Leica M500 N, M520, M525
System description
General
The Leica M500 N / M520 /M525 surgical microscope is an optical instrument which uses magnification and
illumination to improve visibility. It is dedicated mainly for Neurosurgery discipline.
The microscope is always used together with a Leica stand system – refer to product history on page 1-5.
Electrically the optics carrier and the control unit are connected together to the stand system by the CAN bus.
Newer generations of stand systems (like OH4) have their own MDC (microscope device controller) and take over the
task of the M500 N control unit.
Overview control unit M500 N / M520
Display
Switch panel
with 9 keys
Electrical
interfaces
Power inlet*
Power switch*
Grounding socket*
* Only for control
unit with internal
power supply

Description Service manual M500 N, M520, M525
08/2007 Gahe 1-2 Doc Code 10 665 751
Overview optics carrier M525
Drive illumination diaphragm
(M525: Iris override)
M525 only: Iris reset
Handgrip interface
WD lock button
LED WD lock indication
Display WD (M520/M525)
Manual drive WD
Manual drive zoom
Interface for
p
rotective
g
lass
Laser interface
Fiber optics interface
CAN interface
Service & CAN res
A/B slide
Dovetail interface

Service manual M500 N, M520, M525 Description
Doc Code 10 665 751 1-3 08/2007 Gahe
Electrical accessories
- All Leica hand- and footswitches fit to the control unit M500 N / M520 (restriction for 16 function switch – it is
handled as a 12 function switch only)
- CAN handle
- DI C500
- Autofocus device
- Fluorescence devices (available for some stand systems only)
Optical/mechanical accessories
- All optical equipment with dovetail interface fit to the optics carrier. Refer to appropriate stand user manual
for allowed loads and configurations
- Interface for protective glass 10 446 058
- Interface for universal Laser adapter 10 448 079 (M520 & M525)
- Interface for universal Laser adapter 10 446 615 (M500 N)
- Sterilisable knobs
- Interface for right handgrip
- Interface for fiber optic

Description Service manual M500 N, M520, M525
08/2007 Gahe 1-4 Doc Code 10 665 751
Current configurations Leica M525 (state 08/2007)
M525
C40/CT40
M525 MC1
M525 MS3
M525 F40
10448169 control
unit
10448068 control unit
10448144 control
unit
10448237 M525
optics carrier
(with A/B-slide)
10448238 M525
optics carrier
(
no A
/
B slide
)
M525 OH4
10448236 OH4
stand s
y
stem
Control unit M520 not used
anymore - a new controller
is integrated in OH4 system

Service manual M500 N, M520, M525 Description
Doc Code 10 665 751 1-5 08/2007 Gahe
Product history Leica M500N - M520 - M525
Date / event Description: Remark
1997 / Launch M500 N 10 446 481 M500 N optics carrier
10 446 489 control unit
For stand systems OHS1, MS1,
MC1
02/2001 / product change in optics
carrier
10 446 757 M500 N optics carrier
replaces 10 446 481
New emergency drive for zoom
07/2001 / Launch with MS2
10 446 757 M500 N optics carrier
10 446 489 control unit
Additional for MS2 stand system
11/2002 / Launch with OH3
10 711851 control unit for OH3
10 448 019 M500 N optics carrier
(without A/B slide)
Additional for OH3 stand system
04/2003 / Launch with MS3 10 446 757 M500 N optics carrier
10 446 489 control unit
Additional for MS3 stand system
10/2003 / Product change in optics
carrier: New M520 optics carrier
10 448 029 M520 optics carrier
replaces 10 446 757 for MS2, MS3,
OHS1;
10 448 035 M520 optics carrier
(without A/B slide) for OH3
replaces 10 448 019;
Upgrade kit was available:
10 712 316, upgrade kit M500 N to
M520 optics carrier; description 10
665 687;
(10 446 757 to 10 448 070;
10 448 019 to 10448 071)
New illumination unit and new
multifoc objective : More light
30%, increased working distance
from 407 to 470mm, display for
working distance, improved
illumination optics – lead free
glass.
Zoom unit : new diaphragm (10 712
255) for better depth of field -
reduced diameter to 12mm.
New Lemo plug instead fixed CAN
cable – external cable required.
For stand systems OH3, OHS1,
MS3, MS2, MS1, MC1
07/2004 / Launch M520 F40 10 448 029 M520 optics carrier for
F40, 10 448 068 control unit for F40
Control unit without power supply
and with new holder
03/2005 Product change of control
unit: removed power supply
10 448 144 control unit replaces
10 446 489
All stand systems from 03/2005 on
can provide 24V;
09/2005 Product launch M520 C40
and CT40
10 448 029 M520 optics carrier and
new control unit 10 448 169 for C40
and CT40
Control unit compatible, but with
new holder
07/2006 Product change in M520
optics carrier
10 448 029 M520 optics carrier and
10 448 035 M520 optics carrier
with new zoom unit
Paint on zoom lenses as a
diaphragm

Description Service manual M500 N, M520, M525
08/2007 Gahe 1-6 Doc Code 10 665 751
09/2006 Product change to M525
optics carrier
10 448 237 M525 optics carrier
replaces 10 448 029 for MC1, F40,
MS3, C40, CT40
10 448 238 M525 optics carrier
(without A/B slide) replaces
10448 035 for OH4
Upgrade kit available for limited
time:
10 714 461 Upgrade kit M520 to
M525; description 10 665 743
(10 448 029 to 10 448 246;
10 448 035 to 10 448 247)
New illumination unit, additional
AutoIris function, new motor
controller, removed illumination
zoom.
For stand systems OH4, MS3, MC1,
F40, C40, CT40

Service manual M500 N, M520, M525 Description
Doc Code 10 665 751 1-7 08/2007 Gahe
Electrical description
General
The optics carrier is a high performance operating microscope with adjustable working height and integrated zoom,
with M525 also an integrated autoIris. The zoom- and the focus functions, for M525 also the Iris functions, are
microprocessor controlled in order to give the user the maximum comfort. The electronics in the optics-carrier
consists of only one board, with the microprocessor, memory, motorcontrollers and interfaces on it.
A control unit is needed to store the settings, to read hand/footswitches and to control the optics- carrier, manage
CAN bus activities and to display the status/settings. It consists of one controller board, called control module, a LCD
module and a switch panel. Former control units contain a power supply as well.
Overview of system:
Iris function (P8, P9, P10): only in M525
J6
J5
J9J8
P7
CAN
Leica Stand
External. CAN
modul
CAN
Zoom
Multifoc
A
dd.
Funktion
CAN-Bus
RS-232
Service
A
C
DC
max 240VAC
+24V
Optics-carrier
MF off
Control unit
Hand/Footswitch
CAN-Res.
Service
Option*
CAN
CAN-Bus
CAN
Iris control
P7
P1
P3
P6
P2
P4
P5
P8
P9 P10
Iris
CAN-Bus
*Possible options on
CAN bus:
- CAN handle
- DI C500
- Autofocus
- Swing carrier
- Fluorescence

Description Service manual M500 N, M520, M525
08/2007 Gahe 1-8 Doc Code 10 665 751
CAN bus
CAN-bus principle
The CAN-bus (Controller Area Network) is a bi-directional, two-wire bus. It is used to handle the communication
between the control unit, the optics-carrier, the stand and other CAN devices. The CAN-bus uses a protocol which
largely suppresses transmission errors.
The CAN bus in the M500 N/M520/M525 system is operated in the configuration “standard – CAN”.
Data transfer
The bus is looped through each of the controllers. Data is transferred serially, bit by bit, with differential signals. The
data transfer is rated at with 50kBit/s.
The data can be exchanged between each of the controllers. A data transfer consists of:
• Start bit,
• Identification, enabling the priority to be determined,
• The data itself, and
• CRC (Cyclic Redundancy Check).
Each controller recognizes the data related to its task. If a controller wants to send data, it has to wait until the bus is
free. The feature of setting the priority of commands is not applied in the M500 N/M520/M525 system; all commands
have the same priority.
Command interpretation by control unit
The control unit reads CAN commands from CAN handles and from other CAN members. It interprets the received
commands and releases appropriate commands to the CAN bus. The concerning CAN device will then release a
required action.
Safety concept - brake watch dog
The control unit must periodically (100ms) send a brake state message. If no periodic brake state message is received
by the connected stand/brake controller, all brakes will lock.
Terminating impedance
In control unit: the end of the CAN-bus is terminated with an impedance of 120Ω. The controller detects if it is at the
end of the bus or if another device is connected (CAN cable is coded: Pin 4 is bridged to pin 8 in the connector
housing).
In optics carrier: the controller of the optics carrier is always terminated by 120Ω; other devices, connected to the bus
at the optics carrier are not terminated.

Service manual M500 N, M520, M525 Description
Doc Code 10 665 751 1-9 08/2007 Gahe
Optics carrier
Blockdiagram motorcontroller M500 N, M520
Addition for motorcontroller M525:
Powering
The optics-carrier is powered via the CAN-bus cable with +24VDC.
Power consumption is appr.
50mA in wait state,
150mA when one motor is running;
500mA when both motors, focus and zoom are blocked.
A DC/DC converter on the motorcontroller delivers +5V for logic supply. The +24VDC is measured on the controller
board with the microprocessor analog input. It can be asked in the diagnostic menu of the control unit.
Prozessor
H8/532
CAN-
Controller
82527
Zoom-
Motor Driver
EEPROM
Reset
24V 5V
CAN
CAN-Res.
Zoom
P2
P3
CAN-
Trans.
120E
Multifoc
MEM3200
Universal
Counter
Multifoc-
Motor Driver
P4
P5
EPROM
128Kx8
P6
P7
P1
MF off
Option
Service
On-chip
RAM
1kx8
On-chip-
Peripherals,
Watchdog
PWM
PWM
+24V
+24V
SCI
motcontr.ds4
5V
Iris
P8
PWM Iris
Motor Driver
+24V
P10
CAN
P9
Iris control

Description Service manual M500 N, M520, M525
08/2007 Gahe 1-10 Doc Code 10 665 751
Processor
A watch-dog is integrated in the H8-processor. It observes the running of the main program. Diagnosis LED’s might
help with trouble shooting, refer to chapter 4 – fault finding / diagnosis LED’s.
The PWM outputs are driven with the optimum frequency of 20kHz (above the noise-limit, below magnetization
problems).
Motor driver
The zoom- , focus and Iris motors are powered with a +24V PWM-signal. A one-chip controller receives enable-,
direction- and the puls-rate-information from the processor and drives the motors accordingly. All motors have an
encoder mounted directly on the motor axis. The encoder pulses are received by a counter, where the A/B-signals
(direction) are decoded and the actual position transferred further to the processor. A current limitation for the motors
becomes active for current > 0,3A.
Range
The initializing of the microscope sets the lower limit to 1000 encoder-pulses. The actual upper limit is determine with
counting the encoder-pulses (constants are stored for these values; deviations of the displayed values are possible
due to mechanical tolerances).
RS232
A serial interface for service purposes is available. It is directly wired to the Optics-carrier processor - and has
therefore other signal level for TxD than RS232 standard.
Recognition of optics carrier type
Since the increase of the working distance from 407 to 470mm (M500 N to M520) a recognition of the optics carrier
type is required. A bridge on P6 (pin1-pin4) is installed in optics carrier M520 and M525. A status command, requested
from control unit at system start , delivers the information if the bridge is installed or not.
Additional functionality on motorcontroller for M525
The AutoIrsis function in the M525 required an additional motor and a redesign of the motorcontroller. All existing
functions were taken over (backwards compatible) and additional circuits for Iris motor drive and Iris control were
integrated. The movement of the Iris motor is completely handled by the motorcontroller, no direct access via the CAN
bus is possible.
Software history
Software
version
Release date HW motorcontroller Compatibility Remark
1.4 02/98 10 661 250 M500 N
2.3 04/99 -“- M500 N
2.4 05/01 -“- M500 N, M520
4.4 xx/06 10 714 356 M500 N, M520, M525
Software compatibility in respect of control unit see chapter inspection / step 2.13.
or 470mm (M520, M525)
800 1000 upper limit
Zoom OUT Zoom IN
working range
range.ds4
DOWN UP
Focus 207mm Focus 407mmDOWN
UP
Zoom: 28500
Focus: 23800

Service manual M500 N, M520, M525 Description
Doc Code 10 665 751 1-11 08/2007 Gahe
Control unit
Blockdiagram
Powering
Control units before 03/2005 had a power inlet for 230VAC ad the built-in power supply could feed the system with
+24VDC. This was required in stand systems having no own power supply like the MC1.
Since 03/2005 all stand systems have their own power supply. So the power supply was removed from control unit,
now it is supplied via the CAN bus cable with 24VDC.
Processor
An Intel 386EX Processor is used. It is clocked with 20MHz. The memory consists of 256kByte RAM, 256kByte Flash-
EPROM and 4kByte EEPROM. The software can be updated/downloaded through the RS232 service-interface.
A watch-dog is integrated, it observes the running of the main program. Diagnosis LED’s might help with trouble
shooting, refer to chapter 4 – fault finding / diagnosis LED’s.
Processor
CAN-
Controller
82527 Flash-
EPROM
256KByte
EEPROM
4 kByte
Watchdog
Timer
RAM
24V 5V
CAN-
Bus
J2
DC
A
C
Relay
contact
Function
keys
J5
P7
RS232
J8
J3
CAN-
Bus
J6
DUART
"Gold"-
capacitor
J9
J10
RS232
5V 5V
steuerge.ds4
256kByte
2
2
Power-off
Timer
386EX CPU,
PLD Glue Logic,
Bus Transceivers
CLK2
40MHz
CAN-
Trans.
5V
J11
LCD - Gra
p
hic Controlle
r
max 230V AC
LCD - Display
240 x 128 Dots
with VF-backlight
Service,
Download
Hand-/Footswitch 1 and 2
Relay
contact
+24V Power supply
removed since
03/2005

Description Service manual M500 N, M520, M525
08/2007 Gahe 1-12 Doc Code 10 665 751
Display / Keyboard
The communication with the user is done with help of an high-contrast display and a keyboard with nine keys. The
display is a LCD Matrix (240x128 dots) with integrated Graphic controller and backlight.
Can-bus
The CAN-bus has two go-through-input/outputs with two identical parallel connectors.
Hand/Footswitch
There are two RS232 interface-connectors available for all available hand / footswitches. They are wired to the
DUART-interface and are clocked with 4800 Baud. The control unit periodically (60ms) sends a request to the
connected footswitch. It sends back a status code (2 Byte), indicating which key is pressed/not pressed.
Service interface
A double RS232 interface is provided for service purposes. They are both wired directly to the Processor (RXD0/TXD0,
RXD1/TXD1) The connector P7 is used for both of them. COM1 (RXD0/TXD0) is programmed for a service-terminal, for
example for downloading new software version into the Flash-EPROM.
Additional function
There are two relay-contacts on the control unit connector panel for additional functions. The maximum permissible
loading for one contact is 1 A/24 V DC. The relay-contacts can be programmed to switch- or toggle mode.
Software history
Software
version
Release date HW control module Compatibility Remark
1.4 02/98 10 661 330 M500 N
1.54 01/00 -“- M500 N
1.76 04/02 -“- M500 N Supports Can handles, DI C500
1.81 -“- M500 N Supports OH3
1.84 -“- M500 N Supports MS3, CAN handle can
be configured separate
1.87 -“- M500 N, M520, M525 Supports M520, M525
Software compatibility in respect of optics carrier see chapter inspection / step 2.13.

Service manual M500 N, M520, M525 Description
Doc Code 10 665 751 1-13 08/2007 Gahe
Technical data
Optics carrier M525
Stock n° 10448237 M525 optics carrier
10448238 M525 optics carrier OH4
Zoom 6:1 zoom, motorized
Magnification Total magnification with 10x eyepiece 1,2 x to 12,8
Working distance 207-470 mm, variable through motorized multi-focal lens, continuously adjustable;
manually adjustable by emergency knob
Display Analog display of working distance
Field of view (diameter) 16,5mm to 180 mm with 10x eyepiece
Objective Multi-focal lens 207-470 mm variable working distance
Illumination Continually adjustable illumination field diameter with gauss-shaped light distribution
AutoIrisTM Built-in automatic zoom-synchronized illumination filed diameter with manual override and
reset feature
Outlet interface Dovetail ring
Control unit M500 N/M520
Stock n° 10448169 (M525 C40/CT40)
10448068 (M525 F40)
10448144 (MC1, MS3)
Display LCD display
Adjustment of Speed for zoom and focus, brightness and backlight intensity of display, WD and zoom
Interfaces RS232 for service
2x RS232 for foot/handswitch
2x additional function (programmable relay contact)
CAN port Two CAN-ports, 24V max 50W

Description Service manual M500 N, M520, M525
08/2007 Gahe 1-14 Doc Code 10 665 751

Service manual Leica M500 N, M520, M525 Wiring
Doc Code 10 665 751 2-I 07/2007 Gahe
2. Wiring and locations Leica M500 N, M520, M525
Table of content
Chapter Page
Optics carrier 2-1
Control unit 2-4
Overview of connectors 2-6
Wiring diagrams 2-8
Wiring diagram M525 719072 2-9
Wiring diagram M500 N / M520 707276 2-11

Wiring Service manual M500 N, M520, M525
07/2007 Gahe 2-II Doc Code 10 665 751