Dell U2421E User manual

DELL U2421E 1
Use a Philips-head screwdriver to remove 4pcs
screws for unlocking mechanisms. Remove DP cap.
(No.1~4 screw size=M4x11; Torque=11±1kgfxcm)
Take out all accessories including label(optinal), QSG,
Delta-E paper, DP cable, USB C to C cable(Type-C
cable), USB A to C cable(USB cable), power cable
and other packing materials from the carton. (Note: It
depends on whether users returning the accessories)
S2
Open the carton with a proper tool.
1. Disassembly Procedures:
S1
Take out the monitor from EPE-bag and put the LCD
monitor on a protective cushion.
Take out the base and molded plup from the carton,
then take out the monitor and stand from the carton.
S3
S4
S5
Monitor
stand
base
Wedge your fingers between rear cover and the
middle bezel on the corners of the top side of the
monitor to release the rear cover, then use one hand
to press the middle bezel, the other hand to pull up
carefully the rear cover in order of arrow preference
for unlocking mechanisms of rear cover.
S6
S7
3
2
1
2
Lift the rear cover up carefully. Disconnect the
joystick key cable from the connector of the interface
board, and then remove the rear cover and put it
aside for later diasassembling.
Use a Philips-head screwdriver to remove 2pcs
screw for unlocking the key board, then tear off the
tapes and release the key board.
(No.1~2 screw size=M2x2.4, Torque=0.8~1kgfxcm)
S8
1
2
23
41
Delta_E paper
QSG
USB C to C cable
DP cable
power cable
USB A to C cable

2DELL U2421E
S13
S10
S12
Use a Philips-head screwdriver to release 1 screws
for unlocking the USB board, then disconnect the
USB FFC cable away from the connector of the
interface board and remove the Usb board unit.
(No.1screw size=M3x6, Torque=4±0.5kgfxcm)
S11
S9
1
Disconnect the LED cable from the connector of the
interface board. Use a Philips-head screwdriver to
remove 12pcs screws for unlocking the middle bezel
with front bezel.
(No.1~4 screw size=M3x5, )Torque=5±0.5kgfxcm
Lift up and take away the middle bezel, then put it on
a cushion foam. Tear off the tape on the back of
middle bezel for releasing the LED cable, then tear
off the mylar tape for releasing the LED board.
Tear off 1pcs conductive tape for uncovering the
panel lamp connector, then disconnect the panel
lamp cable from the panel and board.
32
1
67
54
8
910
11
12
Tear off 1pcs mylar tape for unfixing the panel lamp
cable, then release the panel lamp cable from the
hooks of the middle bezel.

3
DELL U2421E
S15
S16
Use a Philips-head screwdriver to remove
screws for interface board and power board.
7pcs
(No.1 screw size=M4x8, Torque=7±1kgfxcm;
No.2~7 screw size=M3x7.5, Torque=7±1kgfxcm)
S18
Remove the power board board and interface
board from the
disconnect all of the cables.
bracket chassis module carefully,
and then
S20
Remove the Mylar tape from the hooks of the
bracket.
S17
S19
Tear off 2pcs aluminum foil, and then use a
2pcs screws for
unlocking the bracket with panel module.
Philips-
head screwdriver to remove
(No.1~2 screw size=M3x4, Torque=5±0.5kgfxcm)
Move up the bracket, then push the earing-lock and
disconnect the LVDS cable away from the connectors
of the panel module.
Take away the bracket chassis module and then put
the bracket chassis module on a protective cushion.
2
5
3
1
76
4
4
1

4DELL U2421E
Remove electrolyte capacitors (red mark) from
printed circuit boards.
S20
S20-1 Cut the glue between bulk cap. and PCB with a knife.
S20-2 Ensure cutting path within the glue, don’t touch bulk
cap. or PCB.
S20-4 Take out bulk cap. pin solder with soldering iron and
absorber.
S20-5 Lift the bulk cap. up and away from the PCB.
S20-3 Cut into the bottom of bulk cap. and pullit up
carefully.

5
DELL U2421E
The following substances, preparations, or components should be disposed of or
recovered separately from other WEEE in compliance with Article 4 of EU Council
Directive 75/442/EEC.
Capacitors / condensers (containing
PCB/PCT)
No used
Mercury containing components
No used
Batteries
No used
Printed circuit boards (with a surface
greater than 10 square cm)
Product has printed circuit boards (with a
surface greater than 10 square cm)
Component contain toner, ink and
liquids
No used
Plastic containing BFR
No used
Component and waste contain
asbestos
No used
CRT
No used
Component contain CFC, HCFC, HFC
and HC
No used
Gas discharge lamps
No used
LCD display > 100 cm2
Product has an LCD greater than 100 cm2
External electric cable
Product has external cables
Component contain refractory
ceramic fibers
No used
Component contain radio-active
substances
No used
Electrolyte capacitors (height
> 25mm, diameter > 25mm)
Product has electrolyte capacitors (height >
25mm, diameter > 25mm)
3. 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:
- Screwdriver (Phillip head) #1
- Screwdriver (Phillip head) #2
- Penknife
- Soldering iron and absorber
2. Product material information