Acer KG251Q User manual

Acer Monitor KG251Q
LIFECYCLE EXTENSION
GUIDE

Contents
Table of Contents
Important Safety Notice.................................................................................3
1. Exploded Diagram......................................................................................4
2. Wiring connectivity diagram ....................................................................5
3. Mechanical Instruction..............................................................................6
4. Disassembly and Assembly SOP ............................................................7
5. Troubleshooting.......................................................................................11
6. FRU List .....................................................................................................13
Safety Notice
Any person attempting to service this chassis must familiarize with the chassis and be aware
of the necessary safety precautions to be used when serving electronic equipment containing
high voltage

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Important Safety Notice
Product Announcement:
This product is certificated to meet RoHS Directive and Lead-Free produced definition. Using approved
critical components only is recommended when the situation to replace defective parts. Vender
assumes no liability express or implied, arising out of any unauthorized modification of design or
replacing non-RoHS parts. Service providers assume all liability.
Qualified Repairability:
Proper service and repair is important to the safe, reliable operation of all series products. The
service providers recommended by vender should being aware of notices listed in this service
manual in order to minimize the risk of personal injury when perform service procedures.
Furthermore, the possible existed improper repairing method may damage equipment or products. It
is recommended that service engineers should have repairing knowledge, experience, as well as
appropriate product training per new model before performing the service procedures.
NOTICE:
! To avoid electrical shocks, the products should be connect to an authorized power cord, and turn
off the master power switch each time before removing the AC power cord.
! To prevent the product away from water or explosed in extremely high humility environment.
! To ensure the continued reliability of this product, use only original manufacturer’s specified parts.
! To ensure following safety repairing behavior, put the replaced part on the components side of
PWBA, not solder side.
! To ensure using a proper screwdriver, follow the torque and force listed in assembly and
disassembly procedures to screw and unscrew screws.
! Using Lead-Free solder to well mounted the parts.
! The fusion point of Lead-Free solder requested in the degree of 220°C.

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1. Exploded Diagram
1.1 Product Exploded Diagram
Item
ODM DESCRIPTION
1
ASSY TRIM
2
PCBA CTRL BD
3
MID-FRAME
4
PANEL
5
PCBA IF BD
6
PCBA SPS BD
7
ASSY SHD
8
LVDS
9
SPK
10
ASSY RC
11
ASSY CLMN
12
ASSY BASE

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2. Wiring connectivity diagram
There are two types of wiring diagrams for model KG251Q. The wiring connectivity position will be
different according to the ACTUAL PCBA connector position. Please base on different SKU refer to
below diagram.
NOTE: INF BD= Interface Board, PWR BD=Power Board, CTRL BD= Control Board
1. SKU with USB.
2. SKU without USB.

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3. Mechanical Instruction
Tools Required
List the type and size of the tools that would typically can be used to disassemble the product to a
point
where components and materials requiring selective treatment can be removed.
Tool Description:
- working table
- Screw-driver: Philips-head screwdriver, Hex-head screwdriver
- Knife
- glove
- cleaning cloth
- ESD protection

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4. Disassembly and Assembly SOP
KG251Q
4.1 Disassembly Procedures
Preparation before disassemble
1.Clean the room for disassemble
2.Identify the area for monitor
3.Check the position that the monitors be placed and the quantity of the monitor ;prepare the area for material flow;
according to the actual condition plan the disassemble layout
4.Prepare the implement, equipment, materials as bellow:
1) working table
2) Screw-driver: Philips-head screwdriver, Hex-head screwdriver
3) knife
4) glove
5) cleaning cloth
6) ESD protection
After unplugging the power cord, the power board still have power energe. Please pay attention
when disassembling/assembling.
S1
Disassemble the RC,
stand and base
Before Disassembling & Assembling, monitor need to be put on the sponge and
the Insulation glove must be wore during the process.
Disassemble base and column from the RC(Rear Case).
Unlock RC center screw and as picture 2.
Disassemble RC from monitor.
PICTURE 1 PICTURE 2
S2
Disassemble MF and
Trim
Unlock 8 MF screws and 2 trim screws as picture 1.
Disassemble all tapes, lamp wire and LVDS as picture 2.
PICTURE 1 PICTURE 2

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S3
Disassemble CTRL BD
Tear off CTRL FFC from P/BD and disassemble CTRL BD from Trim
S4
Disassemble I/F BD
and P/BD from SHD.
Disassemble SHD from panel and unlock 5 PCBA screws.
Tear off mylar, extract P/BD wire from the IF BD, disassemble the IF BD from the SHD,
and extract the FFC from the IF BD.
Disassemble the P/BD from the SHD and extract P/BD wire from the P/BD.
S5
Disassemble SPK.
Tear off 1 tape and disassemble speakers.
NOTE: Circuit boards >10 cm² has been highlighted with the yellow rectangle as above image shows.
Please detach the Circuit boards and follow local regulations for disposal.
CTRL BD
P/BD
I/F BD

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4.2 Assembly Procedures
Preparation before assemble:
1.Clean the room for work
2.Identify the area for material
3.Prepare the implement, equipment, materials as bellow：
1) working table
2) Screw-driver: Philips-head screwdriver, Hex-head screwdriver
3) Knife
4) Glove
5) Cleaning cloth
6) ESD protection
After unplugging the power cord, the power board still have power energe. Please pay attention when
disassembling/assembling.
S1
Assemble SPK
Before Disassembling & Assembling, monitor need to be put on the sponge and
the Insulation glove must be wore during the process.
Put the SHD on the worktable.
Assemble speaker and stick 1 tape.
S2
Assemble I/F BD and P/BD
from SHD.
Insert P/BD Wire to P/BD and assemble the P/BD to the SHD.
Insert the FFC wire and P/BD wire to the IF BD and assemble the IF BD to the SHD.
Lock 5 PCBA screws and stick 1 mylar to fasten the wires.

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S3
Assemble Panel to MF
Take the Panel, insert lamp wire to panel marked as red frame.
Assemble the MF to the panel ,and lock 8 screws to the MF as the picture
S4
Assemble CTRL BD
Assemble Crel FFC to Ctrl BD and put them into trim, then lock 2 trim screws
S5
Assemble SHD
Locate the SHD, insert lamp wire to P/BD.
Insert FFC Ctrl to PCBA and insert LVDS to Panel
S7
Assemble the RC, stand
and base
Assemble the RC to the MF and Lock 1 screw as picture 1.
Assemble the column and base on the RC as picture 2.
PICTURE 1 PICTURE 2
NOTE: Circuit boards >10 cm² has been highlighted with the yellow rectangle as above image shows.
Please detach the Circuit boards and follow local regulations for disposal.

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5. Troubleshooting
TROUBLESHOOTING
Before sending your LCD monitor for servicing, please check the trouble-shooting list below
to see if you can self-diagnose the problem.
(VGA Mode)
Problems
Current Status
Remedy
No Picture
LED ON
 Using OSD, adjust brightness and contrast to
maximum or reset to their default settings.
LED OFF
 Check the power switch.
 Check if AC power cord is properly connected to
the monitor.
LED displays amber
color
 Check if video signal cable is properly connected
at the back of monitor.
 Check if the power of computer system is ON.
Abnormal
Picture
Unstable Picture
 Check if the specification of graphics adapter
and monitor is in compliance which may be
causing the input signal frequency mismatch.
Display is missing,
center shift, or too
small or too large in
display size
 Using OSD, adjust RESOLUTION, CLOCK,
CLOCK-PHASE, H-POSITION and V-POSITION
with non-standard signals.
 Using OSD, in case of missing full-screen image,
please select other resolution or other vertical
refresh timing.
 Using OSD, in case of missing full-screen image,
please select other resolution or other vertical
refresh timing.
 Wait for a few seconds after adjusting the size of
the image before changing or disconnecting the
signal cable or powering OFF the monitor.
Abnormal
Sound
(Only
Audio-Input
model)
(Optional)
No sound, or sound
level is too low
 Check the audio cable with the host PC is
connected.
 Check if the volume setup of the host PC is in
minimum position and try to raise the volume
level.

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(HDMI/DP Mode)
Problems
Current Status
Remedy
No Picture
LED ON
 Using OSD, adjust brightness and contrast to
maximum or reset to their default settings.
LED OFF
 Check the power switch.
 Check if AC power cord is properly connected
to the monitor.
LED displays
amber color
 Check if video signal cable is properly
connected at the back of monitor.
 Check if the power of computer system is ON.
Abnormal
Sound
(Only
Audio-Input
model)
(Optional)
No sound, or
sound level is too
low
 Check the audio cable with the host PC is
connected.
 Check if the volume setup of the host PC is in
minimum position and try to raise the volume
level.

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6. FRU List
This chapter gives you the FRU (Field Replaceable Unit) listing in global configurations of
ACER KG251Q. Refer to this chapter whenever ordering for parts to repair or for RMA
(Return Merchandise Authorization).
Please note that WHEN ORDERING FRU PARTS, you should check the most up-to-date
information available on your regional web or channel. For whatever reasons a part number
change is made, it will not be noted on the printed Service Guide. For AUTHORIZED
SERVICE PROVIDERS, your office may have a DIFFERENT part number code from those
given in the FRU list of this printed Service Guide. You MUST use the local FRU list provided
by your regional office to order FRU parts for repair and service of customer machines
NOTE: To scrap or to return the defective parts, you should follow the local government
ordinance or regulations on how to dispose it properly, or follow the rules set by your
regional office on how to return it.
Category
ACER
DESCRIPTION
Description
PART NO.
LCD
LED LCD Panel AUO 24.5'
FHD None Glare
M250HTN01.5 00-Z19 LF
250nit 5ms 1000:1
LCDM25W M250HTN01.5 AUO
Z
KL.24505.003
BOARD
MAIN BOARD 1A2H+S
PCBA IF BD MI 1A2H SPK
KG251Q
55.T8ZM3.001
POWER BOARD 1A2H+S
PCBA SPS BD MI H+S V256HQ
55.T8ZM3.002
FUNCTION KEY BOARD
PCBA CTRL BD SMD B276HL
55.T4HM3.003
IF BD
P/ BD
CTRL BD