Unit UPO1000X Series User manual

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Service Manual
UPO1000X Series products

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Table of Contents
Safety Information 3
General Safety Summary 3
Service Safety Summary 5
Terms in the manual 6
Symbols on the product 6
Perface 7
Supporting Product 7
Operation Information 7
Theory of Operation 7
Power Supply 8
Main Board 8
Keyboard and Display Screen 9
Maintenance 9
ESD Prevention 9
Inspection and Cleaning 9
Exterior Cleaning 10
Screen Cleaning 10
Return Instrument to Maintenance 11
Removal and Replacement Procedure 11
Required Device 11
Removal and Replacement 12
Troubleshooting 24
Service Class 25
Common Problem 25
Required Device 25
Troubleshooting Flowchart 25
After Maintenance 28

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Safety Information
This manual contains information and warnings that must be followed to keep the instrument operating under safety
conditions.
General Safety Summary
Use the product only as specified. In order to use this instrument safely and correctly, please read this manual
thoroughly and keep it for future reference.
This product should be used under the local and national regulation.
For correct and safe operation of the product, it is essential that you follow gernerally accepted procedures in
addition to the safety precautions specified in this manual.
This product is only for trained personnel to use.
Only qualified personnel who are aware of the operation danger can remove the outer case for repair, maintenance or
adjustment.
Before use, always check the product with a known source to be sure it is operating correctly
This product is not suitable for measuring dangerous voltage.
Wearing personal safety equipemnt to prevent electric shock and electric arc blast where dangerous live conductors
are exposed.
You may need to read the safety section of other subassembly to learn the warning and note.
When this device is integrated into the system, the safety of this system is the responsibility of the system assembler.
To avoid fire hazard and personal injury
Use the power cord properly
You can only use the special power cord for the instrument approved by the
local and state standards. Do not use the attached power cord to other
product.
Use the voltage setting properly
Before power on, please ensure that the line selector is in the correct position
of the power supply being used.
Instrument grounding
This product is grounded through the grounding conductor of the power cord.
To avoid electric shock, the grounding conductor must be connected to earth
ground. Before making connections to the input or output terminals of the
product, ensure that the product is properly grounded. Do not disable the
power cord grounding connection.
Power switch disconnect
The power switch disconnects the product from the power source. See
instructions for the location. Do not position the equipment so that it is
difficult to disconnect the power switch; it must remain accessible to the user
at all times to allow for quick disconnection if needed.
Power cord disconnect
The power cord disconnects the product from the power source. See
instructions for the location. Do not position the equipment so that it is
difficult to disconnect the power switch; it must remain accessible to the user
at all times to allow for quick disconnection if needed.
Use correct AC adapter
Only use the sepcified AC adapter for this product.
Connect and disconnect properly
Do not connect or disconnect probes or test leads while they are connected to
a voltage source.
Use only insulated voltage probes, test leads, and adapters supplied with the
product, or indicated by UNI-T to be suitable for the product.

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Observe all specific ratings
To avoid fire or shock hazard, observe all rating and markings on the product.
Consult the product manual for further ratings information before making
connections to the product. Do not exceed the Measurement Category (CAT)
rating and voltage or current rating of the lowest rated individual component of
a product, probe, or accessory. Use caution when using 1:1 test leads because
the probe tip voltage is directly transmitted to the product.
Observe all terminal ratings
To avoid fire or shock hazard, observe all rating and markings on the product.
Consult the product manual for further ratings information before making
connections to the product.
Do not apply a potential to any terminal, including the common terminal, that
exceeds the maximum rating of that terminal.
Do not float the common terminal above the rated voltage for that terminal.
The measurement terminal on this porduction is not rated for connecting
power supply or CAT II, III or IV circuit.
Do not operate without covers
Do not operate this product with covers or panels removed, or with the case
open. Hazardous voltage exposure is possible.
Avoid exposed circuitry
Do not touch exposed connections and components when powered on.
Do not operate with suspected
failures
If you suspect that there is damage to this product, have it inspected by
qualified service personnel.
Disable the product if it is damaged. Do not use the product if it is damaged or
operates incorrectly. If in doubt about safety of the product, turn it off and
disconnect the power cord. Clearly mark the product to prevent its further
operation.
Before use, inspect voltage probes, test leads, and accessories for mechanical
damage and replace when damaged. Do not use probes or test leads if they are
damaged, if there is exposed metal, or if a wear indicator shows.
Examine the exterior of the product before you use it. Look for cracks or
missing pieces.
Use only specified replacement parts.
Use proper fuse
Use only the fuse type and rating specified for this product.
Wear eye protection
Wear eye protection if exposure to high-intensity rays or laser radiation exists.
Do not operate in wet/damp
conditions
Be aware that condensation may occur if the instrument is moved from a cold
to a warm environment.
Do not operate in an explosive
atmosphere
Keep product surfaces clean and
dry
Remove the input signals before you clean the product.
Provide proper ventilation
Refer to the installation instructions in the manual for details on installing the
product so it has proper ventilation.
Slots and openings are provided for ventilation and should never be covered or
otherwise obstructed. Do not push objects into any of the openings.
Provide a safe working
environment
Always place the product in a location convenient for viewing the display and
indicators.
Avoid improper or long-time use the keyboard, pointer abd key panel.
Improper or long-time use will cause grievous injury for keyboard or pointer.
Make sure that your work area is intended for ergonomics standards. Consult
an ergonomist to identify pressure damage.
Be careful when lift and move the product. This product is assembled one or

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multiple hands for lift and move.
Probe and Test Leads
Before connecting probes or test leads, connect the power cord from the power connector to a properly grounded
power outlet.
Keep fingers behind the protective barrier, protective finger guard, or tactile indicator on the probes.
Remove all probes, test leads and accessories that are not in use.
Use only correct Measurement Category (CAT), voltage, temperature, altitude, and amperage rated probes, test leads,
and adapters for any measurement.
Beware of high voltages
Understand the voltage ratings for the probe you are using and do not exceed
those ratings. Two ratings are important to know and understand:
• The maximum measurement voltage from the probe tip to the probe
reference lead.
• The maximum floating voltage from the probe reference lead to earth
ground. These two voltage ratings depend on the probe and your
application. Refer to the Specifications section of the manual for more
information.
Warning: To prevent electrical shock, do not exceed the maximum
measurement or maximum floating voltage of the oscilloscope input.
Connect and disconnect properly
Connect the probe output to the measurement product before connecting the
probe to the circuit under test. Connect the probe reference lead to the
circuit under test before connecting the probe input. Disconnect the probe
input and the probe reference lead from the circuit under test before
disconnecting the probe from the measurement product.
Connect and disconnect properly
De-energize the circuit under test before connecting or disconnecting the
current probe.
Connect the probe reference lead to earth ground only.
Do not connect a current probe to any wire that carries voltages or
frequencies above the current probe voltage rating.
Inspect the probe and
accessories
Before each use, inspect probe and accessories for damage (cuts, tears, or
defects in the probe body, accessories, or cable jacket). Do not use if
damaged.
Grounding reference for
Oscilloscope
Do not float the reference lead of this probe when used with an oscilloscope
with ground as reference. The reference lead must connect to ground
potential (0V).
Use floating measurement
Do not float the reference lead of this probe above to the floating voltage.
Service Safety Summary
The service safety summary section contains additional information required to safely perform service on the
product. Only qualified personnel should perform service procedures. Read this Service safety summary and the
General Safety Summary before performing any service procedures.

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To avoid electric shock
Do not touch exposed connections.
Do not service alone
Do not perform internal service or adjustments of this product unless another
person capable of rendering first aid and resuscitation is present.
Disconnect power
To avoid electric shock, switch off the product power and disconnect the power
cord from the mains power before removing any covers or panels, or opening the
case for servicing.
Use care when servicing with
power on
Dangerous voltages or currents may exist in this product. Disconnect power,
remove battery (if applicable), and disconnect test leads before removing
protective panels, soldering, or replacing components.
Verify safety after repair
Always recheck ground continuity and mains dielectric strength after performing
a repair.
Terms in the manual
These terms may appear in this manual:
Warning: Warning statements identify conditions or practices that could result in injury or loss of life.
Caution: Caution statements identify conditions or practices that could result in damage to this product or
other property.
Symbols on the product
These terms may appear on the product:
DANGER indicates an injury hazard immediately accessible as you read the marking.
WARNING indicates an injury hazard not immediately accessible as you read the marking.
CAUTION indicates a hazard to property including the product.
When this symbol is marked on the product, be sure to consult the manual to find out the nature of the
potential hazards and any actions which have to be taken to avoid them. (This symbol may also be used to
refer the user to ratings in the manual.)

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Perface
This manual contains the service information of the instrument.
Befor maintaining the product, please read General Safety Summary and Service Safety Summary.
Please read the introduction of all procedures. These introductions provide important information to perform the
service correctly, safely and efficiently.
Supporting Product
This manual contains the service information for UPO1204X, UPO1104X and UPO1054X.
Check the header on top of page, headline, table or figure or the specified product name in this manual. Materials
without any specific product name apply to all products in the manual.
Operation Information
The instrument information of installation, operation and networking see attached Help or User’s Manual with the
oscilloscope.
Theory of Operation
This chapter describes the electrical operation of the oscilloscope to the module level. The block diagrams shows the
oscilloscope module interconnections.

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Figure 1 UPO1000X Series Block Diagram
Power Supply
The Power Supply board converts AC line voltage to secondary electric power supply for all internal circuits.
Main Board
The Main boards contain the following functions.
Acquisition System
The Acquisition system begins with the analog signal path and ends with a
digitized signal in memory. The signal enters a channel input, and then passes
through an attenuator and preamplifier. The analog signal from each
preamplifier goes through a digitizer, and then into acquisition memory. The
analog signal from each preamplifier is also distributed to a trigger circuit.
Analog Front End
All analog and digital input are routing to the analog front end. Analog channel
can be magnified or attenuated via front-end circuit and output to the
acquisition ASIC. Digital channel only needs to pass through the front-end
circuit to reach the acquisition ASIC.
Processor
Processing the data the analog front end and the data from keyboard and send
the data collected by analog front panel to the screen according to the input
command by the keyboard.
Power Adaptor
Power supply converts to all voltages used for analog and digital circuits
throughout the system. The standby power supply is used to keep power for
certain parts of the system at all times when AC power is connected to the
instrument.
Powe Supply
Fans
Network Port
Display
Key Panel
Power switch
Signal plate
USB
USB
BNC
BNC
BNC
BNC
BNC
BNC
RS2
32

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Keyboard and Display Screen
Keyboard contains read-keyboard knob and digital logic control, which can send information to the processor on the
mainboard. The front panel also generates probe compensation output signals, provides USB ports and digital logic
signal input interfaces on the front panel, and accommodates the main power switch.
Maintenance
This section contains the information needed to do periodic and corrective maintenance on the oscilloscope.
ESD Prevention
Before servicing this product, read the General Safety Summary and the Service Safety Summary at the front of the
manual, as well as the following ESD information.
Caution:Electrostatic discharge (ESD) can damage any semiconductor component in this instrument.
When performing any service that requires internal access to the instrument, adhere to the following precautions to
avoid damaging internal modules and their components due to electrostatic discharge:
1. Minimize handling of static-sensitive circuit boards and components.
2. Transport and store static-sensitive modules in their static protected containers or on a metal rail. Label any
package that contains static-sensitive boards.
3. Discharge the static voltage from your body by wearing a grounded antistatic wrist strap while handling these
modules.
4. Service static-sensitive modules only at a static-free work station.
5. Do not allow any items capable of generating or holding a static charge on the work station surface.
6. Handle circuit boards by the edges when possible.
7. Do not slide the circuit boards over any surface.
8. Avoid handling circuit boards in areas that have a floor or work-surface covering capable of generating a static
charge.
Inspection and Cleaning
Inspection and Cleaning describes how to inspect for dirt and damage. It also describes how to clean the exterior and
interior of the instrument. Inspection and cleaning are done as preventive maintenance. Preventive maintenance,
when done regularly, may prevent instrument malfunction and enhance its reliability.
Preventive maintenance consists of visually inspecting and cleaning the instrument and using general care when
operating it.
How often to perform maintenance depends on the severity of the environment in which the instrument is used. A
proper time to perform preventive maintenance is just before instrument adjustment.

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Exterior Cleaning
Clean the exterior surfaces of the chassis with a dry lint-free cloth or a soft-bristle brush. If any dirt remains, use a
cloth or swab dipped in a 75% isopropyl alcohol solution. Use a swab to clean narrow spaces around controls and
connectors. Do not use abrasive compounds on any part of the chassis that may damage the chassis.
Clean the On/Standby switch using a cleaning towel dampened with deionized water. Do not spray or wet the switch
itself.
Caution:Avoid the use of chemical cleaning agents which might damage the plastics used in this instrument.
Use only deionized water when cleaning the front-panel buttons. Use a 75% isopropyl alcohol solution as a
cleaner for cabinet parts. Before using any other type of cleaner, consult UNI-T Service Center or
representative.
Inspection - Exterior. Inspect the outside of the instrument for damage, wear, and missing parts. Immediately repair
defects that could cause personal injury or lead to further damage to the instrument.
Table 1：External Inspection Checklist
Item
Inspect for
Repair Action
Cabinet, front panel, and cover
Cracks, scratches, deformations,
damaged hardware.
Repair or replace defective module.
Front-panel knobs
Missing, damaged, or loose knobs
Repair or replace missing or defective
knobs.
Connectors
Broken shells, cracked insulation, and
deformed contacts.
Dirt in connectors.
Repair or replace defective modules.
Clear or brush out dirt.
Carrying handle and cabinet feet
Correct operation.
Repair or replace defective module.
Accessories
Missing items or parts of items, bent
pins, broken or frayed cables, and
damaged connectors.
Repair or replace damaged or missing
items, frayed cables, and defective
modules.
Screen Cleaning
Please use wet tissue or a soft cloth to wipe the dust from the screen and surface.
If the display screen is very dirty, please use a cloth to dipped in distilled water, 75% isopropyl alcohol solution or
glass cleaner to slightly wipe the sceen surface. Only use enough water to wet the cloth or to wipe. Avoid excessive
force, which may damage the display surface.
Caution:Improper cleaner and cleaning way will cause damage to the screen.
Do not use abrasive cleaner or surface cleaner to clear the LCD.
Do not spray water on the LCD surface.
Do not excessive force to wipe the LCD.
Caution: To prevent moisture inside the instrument during external cleaning, do not spray any cleaning
solution onto the screen or instrument directly.

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Return Instrument to Maintenance
Use the original package to repack the instrument for shipping. If the package is not applicable, please contact the
local UNI-T representative for a new packing.
Use industrial stapler or strapping tape to seal the carton.
If the instrument is being shipped to a UNI-T Service Center, enclose the following information:
•The owner’s address
•Name and phone number of a contact person
•Model and serial number of the instrument
•Reason for returning
•A complete description of the service request
Mark the address of the UNI-T Service Center and also your own return address on the shipping carton in two
prominent locations.
Removal and Replacement Procedure
This section contains removal and replacement procedure, please see the replaceable module table and exploded
view. Any module in the chassis that does not have a disassembly and replacement procedure will require the entire
instrument to be returned to the UNI-T Service Center for repair .
Warning：Before executing the process or other process, please read the Safety Summary at the beginning
of this manual. In addition, to prevent injury to maintenance personnel or damage to instrument components,
please read the ESD Prevention.
Befor performing any of the steps in this subsection, disconnect the power cable and line voltage souce. Otherwise,
it may cause grievous injury or death.
Caution：Before remove the instrument to clean, please read the cleaning procedure.
Required Device
Most components in this instrument can be removed with a T8 or T10 quincunx ® screwdriver.
Table 2：Device for Removal and Replacement
No.
Tool’s Name
Description
2
T8, T10, T15 quincunx
screwdriver
Remove the screws of the instrument
4
9/16 inch open-end wrench
Remove the screw studs
5
ESD prevention
To prevent static damage to the components while working on the
instrument, wear properly grounded anti-static wristbands and
foot bands, and use anti-static pads in a tested anti-static
environment.

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Removal and Replacement
Remove Front Panel
The following process is describes the removal and replacement of knob module on the front panel. Seven knob
modules can be remove from the front panel.
Precondition
• Whenever you work on the insturment, you should wear grounded anti-static wristbands and foot bands, and use
anti-static pads in a tested anti-static environment.
Steps
1. Pull out the knob module directly from the front shroud by hands. Hands force is enough to remove the knobs
module. Do not use pliers.
2. Align the knobs to axle indentation for reinstallation. Rotate the knobs to ensure the knobs is properly reinstalled
and can be rotate smoothly.
Remove Rear Panel
The following process is describes the removal and replacement of rear panel.
Precondition
•To prevent static damage to the components while working on the instrument, wear properly grounded anti-static
wristbands and foot bands, and use anti-static pads in a tested anti-static environment.
Steps
1. Dismantle gum.

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2. Use T8 quincunx screwdriver to remove two screws from handle.
3. Remove two screws from the bottom of case and then to take off the rear panel.

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4. If you want to reinstall the rear panel, execute the steps in reverse. Use T8 quincunx screwdriver to fix the screw.
Remove Rear Mdule
The following process is describes the removal and replacement of rear module.
Precondition
•To prevent static damage to the components while working on the instrument, wear properly grounded anti-static
wristbands and foot bands, and use anti-static pads in a tested anti-static environment.
•Take down the rear panel.
Steps
1. Use T10 quincunx screwdriver to move M3 screws on the top side.

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2. Use 9/16 inch open-end wrentch to remove two BNC nuts and washers.
3. Open the rear moduel and plug out the power cable from the mainboard.

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4. Put down the front module and rear module, and plug out FPC cable from the mainboard.

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5. If you want to reinstall the rear panel, execute the steps in reverse.
Remoce Power Module
The following process is describes the removal and replacement of power module.
Precondition
•To prevent static damage to the components while working on the instrument, wear properly grounded anti-static
wristbands and foot bands, and use anti-static pads in a tested anti-static environment.
•Take down the rear panel.
•Remove the rear module.
Steps
1. Use T10 quincunx screwdriver to move four screws from the rear panel and take down the power cover.

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2. Plug out the power cable and fan’s power cable, use T10 quincunx screwdriver to move three screws on power
module and take down the power module.
3. If you want to reinstall the rear panel, execute the steps in reverse.
Remove Fan
The following process is describes the removal and replacement of power module.
Precondition

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•To prevent static damage to the components while working on the instrument, wear properly grounded anti-static
wristbands and foot bands, and use anti-static pads in a tested anti-static environment.
•Take down the rear panel.
•Remove the rear module.
•Remove the power cover.
Steps
1. Disconnect the fan’s cable from power supply.
2. Use T15 quincunx screwdriver to move four screws on four sides and take down the fan.

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3. If you want to reinstall the rear panel, execute the steps in reverse.
Remove Front Panel
The following process is describes the removal and replacement of front panel.
Precondition
•To prevent static damage to the components while working on the instrument, wear properly grounded anti-static
wristbands and foot bands, and use anti-static pads in a tested anti-static environment.
•Take down the knobs on the front panel.
•Remove the rear cover.
•Remove the rear module.
Steps
1. Take down the knobs on the front panel.