Service Manual
Table Of Contents
- Latitude 3520 Service Manual
- Working inside your computer
- Removing and installing components
- Recommended tools
- Screw List
- Major components of your system
- MicroSD-card
- SIM card tray
- Base cover
- Battery cable
- Battery
- Memory module
- M.2 solid-state drive thermal plate
- M.2 solid-state drive conversion bracket
- M.2 solid-state drive
- Hard-disk drive
- WLAN card
- WWAN card
- I/O cable
- Display assembly
- System fan
- Heatsink assembly
- Power adapter port
- Coin-cell battery
- USB cable
- Ethernet port
- I/O board
- Power-button board
- System board
- Speakers
- Touchpad
- WWAN I/O board
- Palmrest assembly
- Display bezel
- Display panel
- Camera
- Display cable
- Display back-cover
- Drivers and downloads
- System setup
- Troubleshooting
- Built-in self-test (BIST)
- LCD Built-in Self Test (BIST)
- Dell SupportAssist Pre-boot System Performance Check diagnostics
- Diagnostic LED behavior
- Diagnostic error messages
- System error messages
- Recovering the operating system
- Real-Time Clock (RTC Reset)
- Flashing the BIOS
- Backup media and recovery options
- WiFi power cycle
- Flea power release
- Getting help and contacting Dell
Table 23. Diagnostic error messages
Error messages Description
TIMER CHIP COUNTER 2 FAILED
A chip on the system board may be malfunctioning. Run the
System Set tests in Dell Diagnostics.
UNEXPECTED INTERRUPT IN PROTECTED MODE
The keyboard controller may be malfunctioning, or a memory
module may be loose. Run the System Memory tests and the
Keyboard Controller test in Dell Diagnostics or Contact
Dell.
X:\ IS NOT ACCESSIBLE. THE DEVICE IS NOT
READY
Insert a disk into the drive and try again.
System error messages
Table 24. System error messages
System message Description
Alert! Previous attempts at booting this
system have failed at checkpoint [nnnn]. For
help in resolving this problem, please note
this checkpoint and contact Dell Technical
Support
The computer failed to complete the boot routine three
consecutive times for the same error.
CMOS checksum error
RTC is reset, BIOS Setup default has been loaded.
CPU fan failure
CPU fan has failed.
System fan failure
System fan has failed.
Hard-disk drive failure
Possible hard disk drive failure during POST.
Keyboard failure
Keyboard failure or loose cable. If reseating the cable does not
solve the problem, replace the keyboard.
No boot device available
No bootable partition on hard disk drive, the hard disk drive
cable is loose, or no bootable device exists.
● If the hard drive is your boot device, ensure that the
cables are connected and that the drive is installed
properly and partitioned as a boot device.
● Enter system setup and ensure that the boot sequence
information is correct.
No timer tick interrupt
A chip on the system board might be malfunctioning or
motherboard failure.
NOTICE - Hard Drive SELF MONITORING SYSTEM
has reported that a parameter has exceeded
its normal operating range. Dell recommends
that you back up your data regularly. A
parameter out of range may or may not
indicate a potential hard drive problem
S.M.A.R.T error, possible hard disk drive failure.
Recovering the operating system
When your computer is unable to boot to the operating system even after repeated attempts, it automatically starts Dell
SupportAssist OS Recovery.
Dell SupportAssist OS Recovery is a standalone tool that is preinstalled in all Dell computers installed with Windows 10 operating
system. It consists of tools to diagnose and troubleshoot issues that may occur before your computer boots to the operating
system. It enables you to diagnose hardware issues, repair your computer, back up your files, or restore your computer to its
factory state.
Troubleshooting
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