Dell Chromebook 3400 User manual

Dell Chromebook 3400
Service Manual
Regulatory Model: P101G
Regulatory Type: P101G001

Notes, cautions, and warnings
NOTE: A NOTE indicates important information that helps you make better use of your product.
CAUTION: A CAUTION indicates either potential damage to hardware or loss of data and tells you how to avoid the problem.
WARNING: A WARNING indicates a potential for property damage, personal injury, or death.
© 2019 Dell Inc. or its subsidiaries. All rights reserved. Dell, EMC, and other trademarks are trademarks of Dell Inc. or its subsidiaries. Other trademarks
may be trademarks of their respective owners.
2019 - 03
Rev. A00

Contents
1 Working on your computer............................................................................................................................. 5
Safety instructions.............................................................................................................................................................5
Storing Chromebooks for long term - best practices....................................................................................................5
Before working inside your computer..............................................................................................................................6
After working inside your computer.................................................................................................................................6
2 Technology and components..........................................................................................................................7
USB features.......................................................................................................................................................................7
USB 3.0/USB 3.1 Gen 1 (SuperSpeed USB)............................................................................................................. 7
Speed.............................................................................................................................................................................8
Applications...................................................................................................................................................................8
Compatibility................................................................................................................................................................. 9
Keyboard............................................................................................................................................................................. 9
Keyboard keys function............................................................................................................................................... 9
Touchpad........................................................................................................................................................................... 10
Bluetooth............................................................................................................................................................................ 11
3 Removing and Installing................................................................................................................................13
microSD card.....................................................................................................................................................................13
Removing microSD card............................................................................................................................................ 13
Installing microSD card...............................................................................................................................................13
Base cover.........................................................................................................................................................................14
Removing the base cover..........................................................................................................................................14
Installing the base cover.............................................................................................................................................17
Battery............................................................................................................................................................................... 19
Lithium-ion battery precautions................................................................................................................................19
Removing the battery................................................................................................................................................20
Installing the battery..................................................................................................................................................22
Speaker............................................................................................................................................................................. 25
Removing the speakers.............................................................................................................................................25
Installing the speakers............................................................................................................................................... 28
Input Output board...........................................................................................................................................................31
Removing the Input and output board..................................................................................................................... 31
Installing Input output board.....................................................................................................................................34
Keyboard interposer board..............................................................................................................................................37
Removing the keyboard interposer board............................................................................................................... 37
Installing the keyboard interposer board................................................................................................................. 39
Keyboard............................................................................................................................................................................41
Removing the keyboard............................................................................................................................................. 41
Installing the keyboard...............................................................................................................................................43
System board................................................................................................................................................................... 45
Removing the system board.....................................................................................................................................45
Installing system board..............................................................................................................................................50
Contents 3

Display assembly.............................................................................................................................................................. 55
Removing display assembly...................................................................................................................................... 55
Installing display assembly.........................................................................................................................................58
Display bezel......................................................................................................................................................................61
Removing display bezel..............................................................................................................................................61
Installing display bezel................................................................................................................................................64
Display panel.....................................................................................................................................................................66
Removing display panel.............................................................................................................................................66
Installing display panel............................................................................................................................................... 68
Display hinges................................................................................................................................................................... 70
Removing display hinge.............................................................................................................................................70
Installing display hinge................................................................................................................................................ 71
Display cable..................................................................................................................................................................... 72
Removing display cable............................................................................................................................................. 72
Installing display cable................................................................................................................................................73
Camera.............................................................................................................................................................................. 74
Removing camera.......................................................................................................................................................74
Installing camera.........................................................................................................................................................75
Display back cover........................................................................................................................................................... 76
Replacing display back cover and antenna assembly............................................................................................ 76
Palm rest........................................................................................................................................................................... 78
Replacing palmrest assembly....................................................................................................................................78
4 Troubleshooting........................................................................................................................................... 80
Basic troubleshooting......................................................................................................................................................80
Power issues...............................................................................................................................................................80
CROSH..............................................................................................................................................................................84
CROSH commands......................................................................................................................................................... 85
Chrome commands......................................................................................................................................................... 86
Commonly used CROSH command.............................................................................................................................. 92
Check battery charging status.................................................................................................................................92
Reset Chromebook..........................................................................................................................................................99
Recovery Chromebook.................................................................................................................................................. 104
Recovering the Chromebook..................................................................................................................................104
5 Getting help............................................................................................................................................... 108
Contacting Dell............................................................................................................................................................... 108
4Contents

Working on your computer
Safety instructions
Prerequisite
Use the following safety guidelines to protect your computer from potential damage and to ensure your personal safety. Unless otherwise
noted, each procedure included in this document assumes that the following conditions exist:
• You have read the safety information that shipped with your computer.
• A component can be replaced or, if purchased separately, installed by performing the removal procedure in reverse order.
About this task
WARNING: Disconnect all power sources before opening the computer cover or panels. After you nish working inside the
computer, replace all covers, panels, and screws before connecting to the power source.
WARNING: Before working inside your computer, read the safety information that shipped with your computer. For additional
safety best practices information, see the Regulatory Compliance Homepage
CAUTION: Many repairs may only be done by a certied service technician. You should only perform troubleshooting and simple
repairs as authorized in your product documentation, or as directed by the online or telephone service and support team.
Damage due to servicing that is not authorized by Dell is not covered by your warranty. Read and follow the safety instructions
that came with the product.
CAUTION: To avoid electrostatic discharge, ground yourself by using a wrist grounding strap or by periodically touching an
unpainted metal surface at the same time as touching a connector on the back of the computer.
CAUTION: Handle components and cards with care. Do not touch the components or contacts on a card. Hold a card by its
edges or by its metal mounting bracket. Hold a component such as a processor by its edges, not by its pins.
CAUTION: When you disconnect a cable, pull on its connector or on its pull-tab, not on the cable itself. Some cables have
connectors with locking tabs; if you are disconnecting this type of cable, press in on the locking tabs before you disconnect the
cable. As you pull connectors apart, keep them evenly aligned to avoid bending any connector pins. Also, before you connect a
cable, ensure that both connectors are correctly oriented and aligned.
NOTE: The color of your computer and certain components may appear dierently than shown in this document.
Storing Chromebooks for long term - best practices
Prior to long term (Summer) storage:
1 Update to the latest version of the Chrome OS and charge your Chromebooks so that the battery is at least 80% full.
a This ensures that even when the battery discharges while unplugged over the summer, it will not fully run out of power.
2 Connect the device to a charger and then turn it on.
3 Hold Refresh and Power keys at the same time.
4 While holding these keys, remove the power cable from the device and then release the keys. The device should shut down and
remain o.
5 Attempt to power the unit on, by pressing the power button. If the unit does not power on, you have completed the steps and can
safely store the system. If the unit powers on, you should repeat steps 2 to 4.
Upon redeploying:
1
Working on your computer 5

1 Connect the Chromebooks to a charger and a power source, which will get them out of the battery disconnect state. Power up your
device.
2 Connect your Chromebooks to WiFi and update them to the latest Chrome OS release.
a This can take time, as multiple Chrome OS versions may have been released since the last time the device was updated.
Before working inside your computer
About this task
To avoid damaging your computer, perform the following steps before you begin working inside the computer.
Steps
1 Ensure that you follow the Safety Instruction.
2 Ensure that your work surface is at and clean to prevent the computer cover from being scratched.
3 Turn o your computer.
4 Disconnect all network cables from the computer.
CAUTION: To disconnect a network cable, rst unplug the cable from your computer and then unplug the cable from
the network device.
5 Disconnect your computer and all attached devices from their electrical outlets.
6 Press and hold the power button while the computer is unplugged to ground the system board.
NOTE: To avoid electrostatic discharge, ground yourself by using a wrist grounding strap or by periodically touching an
unpainted metal surface at the same time as touching a connector on the back of the computer.
After working inside your computer
About this task
After you complete any replacement procedure, ensure that you connect any external devices, cards, and cables before turning on your
computer.
Steps
1 Connect any telephone or network cables to your computer.
CAUTION: To connect a network cable, rst plug the cable into the network device and then plug it into the
computer.
2 Connect your computer and all attached devices to their electrical outlets.
3 Turn on your computer.
4 If required, verify that the computer works correctly by running ePSA diagnostics.
6Working on your computer

Technology and components
NOTE: Instructions provided in this section are applicable on computers shipped with Windows 10 operating system. Windows 10
is factory-installed with this computer.
Topics:
• USB features
• Keyboard
• Touchpad
• Bluetooth
USB features
Universal Serial Bus, or USB, was introduced in 1996. It dramatically simplied the connection between host computers and peripheral
devices like mice, keyboards, external drivers, and printers.
Let's take a quick look on the USB evolution referencing to the table below.
Table 1. USB evolution
Type Data Transfer Rate Category Introduction Year
USB 2.0 480 Mbps High Speed 2000
USB 3.0/USB 3.1 Gen 1 5 Gbps Super Speed 2010
USB 3.1 Gen 2 10 Gbps Super Speed 2013
USB 3.0/USB 3.1 Gen 1 (SuperSpeed USB)
For years, the USB 2.0 has been rmly entrenched as the de facto interface standard in the PC world with about 6 billion devices sold, and
yet the need for more speed grows by ever faster computing hardware and ever greater bandwidth demands. The USB 3.0/USB 3.1 Gen 1
nally has the answer to the consumers' demands with a theoretically 10 times faster than its predecessor. In a nutshell, USB 3.1 Gen 1
features are as follows:
• Higher transfer rates (up to 5 Gbps)
• Increased maximum bus power and increased device current draw to better accommodate power-hungry devices
• New power management features
• Full-duplex data transfers and support for new transfer types
• Backward USB 2.0 compatibility
• New connectors and cable
The topics below cover some of the most commonly asked questions regarding USB 3.0/USB 3.1 Gen 1.
2
Technology and components 7

Speed
Currently, there are 3 speed modes dened by the latest USB 3.0/USB 3.1 Gen 1 specication. They are Super-Speed, Hi-Speed and Full-
Speed. The new SuperSpeed mode has a transfer rate of 4.8Gbps. While the specication retains Hi-Speed, and Full-Speed USB mode,
commonly known as USB 2.0 and 1.1 respectively, the slower modes still operate at 480Mbps and 12Mbps respectively and are kept to
maintain backward compatibility.
USB 3.0/USB 3.1 Gen 1 achieves the much higher performance by the technical changes below:
• An additional physical bus that is added in parallel with the existing USB 2.0 bus (refer to the picture below).
• USB 2.0 previously had four wires (power, ground, and a pair for dierential data); USB 3.0/USB 3.1 Gen 1 adds four more for two pairs
of dierential signals (receive and transmit) for a combined total of eight connections in the connectors and cabling.
• USB 3.0/USB 3.1 Gen 1 utilizes the bidirectional data interface, rather than USB 2.0's half-duplex arrangement. This gives a 10-fold
increase in theoretical bandwidth.
With today's ever increasing demands placed on data transfers with high-denition video content, terabyte storage devices, high megapixel
count digital cameras etc., USB 2.0 may not be fast enough. Furthermore, no USB 2.0 connection could ever come close to the 480Mbps
theoretical maximum throughput, making data transfer at around 320Mbps (40MB/s) — the actual real-world maximum. Similarly, USB
3.0/USB 3.1 Gen 1 connections will never achieve 4.8Gbps. We will likely see a real-world maximum rate of 400MB/s with overheads. At this
speed, USB 3.0/USB 3.1 Gen 1 is a 10x improvement over USB 2.0.
Applications
USB 3.0/USB 3.1 Gen 1 opens up the laneways and provides more headroom for devices to deliver a better overall experience. Where USB
video was barely tolerable previously (both from a maximum resolution, latency, and video compression perspective), it's easy to imagine
that with 5-10 times the bandwidth available, USB video solutions should work that much better. Single-link DVI requires almost 2Gbps
throughput. Where 480Mbps was limiting, 5Gbps is more than promising. With its promised 4.8Gbps speed, the standard will nd its way
into some products that previously weren't USB territory, like external RAID storage systems.
Listed below are some of the available SuperSpeed USB 3.0/USB 3.1 Gen 1 products:
• External Desktop USB 3.0/USB 3.1 Gen 1 Hard Drives
• Portable USB 3.0/USB 3.1 Gen 1 Hard Drives
• USB 3.0/USB 3.1 Gen 1 Drive Docks & Adapters
• USB 3.0/USB 3.1 Gen 1 Flash Drives & Readers
• USB 3.0/USB 3.1 Gen 1 Solid-state Drives
8Technology and components

• USB 3.0/USB 3.1 Gen 1 RAIDs
• Optical Media Drives
• Multimedia Devices
• Networking
• USB 3.0/USB 3.1 Gen 1 Adapter Cards & Hubs
Compatibility
The good news is that USB 3.0/USB 3.1 Gen 1 has been carefully planned from the start to peacefully co-exist with USB 2.0. First of all,
while USB 3.0/USB 3.1 Gen 1 species new physical connections and thus new cables to take advantage of the higher speed capability of
the new protocol, the connector itself remains the same rectangular shape with the four USB 2.0 contacts in the exact same location as
before. Five new connections to carry receive and transmitted data independently are present on USB 3.0/USB 3.1 Gen 1 cables and only
come into contact when connected to a proper SuperSpeed USB connection.
Windows 10 will be bringing native support for USB 3.1 Gen 1 controllers. This is in contrast to previous versions of Windows, which
continue to require separate drivers for USB 3.0/USB 3.1 Gen 1 controllers.
Keyboard
Dell keyboards have a few extra features to help you browse the web eortlessly and eciently. The keyboard contains a dedicated search
key and a new row of web shortcut keys. A standard USB Windows keyboard can also be used with the Chromebook, using the same
keyboard shortcuts. The image below shows the keyboard layout.
Keyboard keys function
The Chrome device keyboard is designed to help you get to the things you need the most. The table below is an overview of the special
keys on the top row of the keyboard:
Table 2. Special keys
Special keys
Go to the previous page in browser history
Go to the next page in browser history
Reload current page
Enter Immersive mode, which hides the tabs and launcher
Enter Overview mode, which shows all windows
Decrease screen brightness
Technology and components 9

Special keys
Increase screen brightness
Mute
Decrease the volume
Increase the volume
Search applications and the web at the same time. On a Chromebook, this key is on the side, where the Caps Lock key
is normally located.
Keyboard shortcut keys
Table 3. Shortcut keys
Shortcut keys
Function Combination keys
Page up Press Alt and the up arrow
Page down Press Alt and the down arrow
Home Press Ctrl+Alt, and the up arrow
End Press, Ctrl+Alt and the down arrow
Delete Press Alt+Backspace
Toggle the bookmark bar Ctrl+Shift+B
Search current webpage Ctrl+F
Open a new tab Ctrl+T
Open a new window Ctrl+N
Open the link you clicked in a new background tab Press Alt and click a link
Switch to next tab Ctrl+Tab
Sign out of Google Account Ctrl+Shift+Q
Close current tab Ctrl+W
To see more shortcuts, simply press Ctrl+Alt+? To open the keyboard viewer on your screen.
Touchpad
This page contains information for Dell touchpad gestures.
The following table lists some gestures and actions supported by the Chromebook touchpad:
10 Technology and components

Table 4. Touch pad gestures
Touchpad gestures
Gestures Explanation
Simply move your nger across the touchpad.
Press down on the lower half of the touchpad. Since tap-to-click is enabled by default, you can quickly tap the
touchpad to click.
Click the touchpad with two ngers.
Place two ngers on the touchpad and move them up and down to scroll vertically, left and right to scroll
horizontally. If you have Australian scrolling enabled, move two ngers up to scroll down. (It works in the same
way as say, your smartphone or tablet.) If you have multiple browser tabs open, you can also swipe left and
right with three ngers to quickly move between tabs.
Swipe Quickly move two ngers left or right to go backward or forward on web pages or while using apps.
Click the item you want to move with one nger. With a second nger, move the item. Release both ngers to
drop the item at its new location.
Bluetooth
This section outlines the instruction to pair a bluetooth device with your Chrome devices.
Bluetooth technology lets you connect devices wirelessly over short distances. To use the Bluetooth accessories with your Chromebook,
rst check if your Chromebook supports Bluetooth. You will then need to pair it with the accessory.
To see if you can use the Bluetooth accessories with your Chromebook, click the status area in the lower right corner, where your account
picture appears. If you see the Bluetooth icon or in the menu, your Chromebook supports Bluetooth. If you do not see either of
Technology and components 11

these icons, your Chromebook does not support Bluetooth. If your Chromebook supports Bluetooth, it can connect to a wide range of the
Bluetooth accessories, including the following:
• Keyboards
• Mice
• Speakers
• Headphones
• Headsets (audio only)
To connect a Bluetooth device with your Chromebook, you need to pair them. Here is how:
1 Sign in to your Chromebook.
2 Click the status area in the lower-right corner, where your account picture appears.
3 Select your Bluetooth status in the menu that appears.
4 If Bluetooth is disconnected, click the disconnected icon. or click Enable Bluetooth in the menu. Your Chromebook will
automatically begin scanning for available Bluetooth devices.
5 Pick the device you want to add from the list of available Bluetooth devices and click Connect.
6 Follow the instructions on the screen to connect your Bluetooth device.
• If you are connecting a mouse, no PIN is normally required. If you are prompted for a PIN, enter the PIN for your mouse using your
Chrome device's keyboard.
• If you are connecting a keyboard, enter the randomly generated PIN on the keyboard you wish to pair and press Enter.
To conrm that your Bluetooth device is connected, check the Bluetooth status. You should see your device listed there.
NOTE: Just got your Chromebook or Chromebox? If you are turning on your chrome device for the rst time and you have a
Bluetooth device nearby that is also turned on, your chrome device may automatically detect the device and show you steps to
pair it. You will see these instructions only if your chrome device does not already have a similar device connected or its
functionality is not built in, like a keyboard or trackpad.
12 Technology and components

Removing and Installing
microSD card
Removing microSD card
Prerequisite
Follow the procedure in before working inside your computer.
Steps
1 Press the microSD card to release it from the computer [1].
2 Remove the microSD card from the computer [2].
Installing microSD card
Step
Slide the SD card into its slot until it clicks into place [1, 2].
3
Removing and Installing 13

Next step
Follow the procedure in after working inside your computer.
Base cover
Removing the base cover
Prerequisites
1 Follow the procedure in before working inside your computer.
2 Remove the microSD card.
Steps
1 Loosen the 11 captive screws that secure the base cover to the computer.
14 Removing and Installing

2 Pry the base cover from the edge using a plastic scribe [1, 2].
Removing and Installing 15

NOTE: While removing the base cover, on-site technicians must take care to remove the base cover carefully. There are
prying recess points next to the left and right hinges which ease the disassembly procedure. With the help of a plastic
scribe, pry open from the top left side of the base cover, continue working your way around the left and right side of the
base cover, then remove the base cover from the system.
3 Lift the base cover from the computer.
16 Removing and Installing

Installing the base cover
Steps
1 Align the base cover on the computer and press the edges of the cover until it clicks into place.
Removing and Installing 17

2 Tighten the 11 captive screws to secure the base cover to the computer.
18 Removing and Installing

Next steps
1 Install the microSD card.
2 Follow the procedure in after working inside your computer.
Battery
Lithium-ion battery precautions
CAUTION:
• Exercise caution when handling Lithium-ion batteries.
• Discharge the battery as much as possible before removing it from the system. This can be done by disconnecting the AC adapter
from the system to allow the battery to drain.
• Do not crush, drop, mutilate, or penetrate the battery with foreign objects.
• Do not expose the battery to high temperatures, or disassemble battery packs and cells.
• Do not apply pressure to the surface of the battery.
• Do not bend the battery.
• Do not use tools of any kind to pry on or against the battery.
• If a battery gets stuck in a device as a result of swelling, do not try to free it as puncturing, bending, or crushing a Lithium-ion
battery can be dangerous. In such an instance, the entire system should be replaced. Contact https://www.dell.com/support for
assistance and further instructions.
• Always purchase genuine batteries from https://www.dell.com or authorized Dell partners and re-sellers.
Removing and Installing 19

Removing the battery
Prerequisites
1 Follow the procedure in before working inside your computer
2 Remove the microSD card.
3 Remove the base cover.
Steps
1 Disconnect the battery cable from the connector in the system board [1].
2 Unroute the battery cable from the routing channel [2].
3 Remove the three (M2.0x4.0) screws that secure the battery to the palmrest [1].
4 Peel the adhesive tape that secures the battery in place [2, 3].
20 Removing and Installing