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HP ProDesk 400 G7 Maintenance and Service Guide - Page 73

Power light blinks red three times and then white two times

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Power light blinks red three times and then white two times Use this information to troubleshoot the computer. Cause Memory is installed incorrectly or is bad. Solution To avoid damage to the DIMMs or the system board, you must unplug the computer power cord before attempting to reseat, install, or remove a DIMM module. 1. Reseat DIMMs. Turn on the system. 2. Replace DIMMs one at a time to isolate the faulty module. NOTE: DIMM1 or XMM1 must always be installed. DIMM1 must be installed before DIMM3. 3. Replace third-party memory with HP memory. 4. Replace the system board. ENWW Solving hardware installation problems 65

Section	Page
Product features	9
Standard configuration features	9
Front panel components	9
Rear panel components	10
Serial number location	11
Illustrated parts catalog	13
Computer major components	13
Mass storage devices	16
Cables	17
Miscellaneous parts	18
Routine care, SATA drive guidelines, and disassembly preparation	19
Electrostatic discharge information	20
Generating static electricity	20
Preventing electrostatic damage to equipment	21
Personal grounding methods and equipment	21
Grounding the work area	21
Recommended materials and equipment	22
Operating guidelines	22
Routine care	24
General cleaning safety precautions	24
Cleaning the computer case	24
Cleaning the keyboard	24
Cleaning the monitor	25
Cleaning the mouse	25
Service considerations	26
Tools and software requirements	26
Screws	26
Cables and connectors	26
Hard drives	26
Lithium coin cell battery	27
SATA hard drives	27
Cable management	28
Removal and replacement procedures	29
Preparation for disassembly	29
Access panel	29
Optical drive	30
Front bezel	31
Hood sensor module	32
Memory modules (DIMMs)	33
Expansion card	36
Drive cage	37
Hard drive	38
Speaker	42
WLAN module	43
Solid-state drive	45
Fan shroud	46
Heat sink	47
Processor	48
Power supply	50
Battery	51
System board	54
Troubleshooting without diagnostics	57
Before you call for technical support	57
Helpful hints	58
Solving general problems	59
Cannot access the Computer Setup (F10) Utility when booting the computer	59
Computer appears locked up and will not turn off when the power button is pressed	59
Computer will not respond to keyboard or mouse	59
Computer date and time display is incorrect	59
There is no sound or sound volume is too low	60
Cannot remove computer cover or access panel	60
Poor performance	60
Computer powered off automatically and the power light blinks red four times and then white two time ...	61
System does not turn on and the lights on the front of the computer are not blinking	61
Solving power problems	63
Power supply shuts down intermittently	63
Computer turned off automatically, power light blinks red two times followed by a two-second pause, ...	63
Power light blinks red four times followed by a two-second pause and the computer beeps four times ( ...	63
Solving hard drive problems	65
Hard drive error occurs	65
Disk transaction problem	65
Drive not found (identified)	65
Nonsystem disk/NTLDR missing message	65
Computer will not boot from hard drive	66
Computer seems to be locked up	66
Solving audio problems	67
Sound cuts in and out	67
Sound does not come out of the speaker or headphones	67
Computer appears to be locked up while recording audio	67
Line-in jack is not functioning properly	68
Solving printer problems	69
Printer will not print	69
Printer will not turn on	69
Printer prints garbled information	69
Printer will not print	69
Solving keyboard and mouse problems	71
Keyboard commands and typing are not recognized by the computer	71
Mouse does not respond to movement or is too slow	71
Solving hardware installation problems	72
A new device is not recognized as part of the system	72
Computer will not start	72
Power light blinks red three times and then white two times	73
Solving network problems	74
Network driver does not detect network controller	74
Network status link light never blinks	74
Diagnostics reports a failure	74
Diagnostics passes, but the computer does not communicate with the network	75
Network controller stopped working when an expansion board was added to the computer	75
Network controller stops working without apparent cause	75
Cannot connect to network server when attempting remote system installation	75
System setup utility reports unprogrammed EEPROM	76
Solving memory problems	77
System will not boot or does not function properly after installing additional memory modules	77
Out of memory error	77
Memory count during POST is wrong	77
Insufficient memory error during operation.	78
Power light blinks red five times followed by a two-second pause and the computer beeps five times ( ...	78
Solving USB flash drive problems	79
USB flash drive is not seen as a drive letter in Windows	79
USB flash drive not found (identified)	79
System will not boot from USB flash drive	79
The computer boots to DOS after making a bootable flash drive	79
Solving internet access problems	80
Unable to connect to the internet	80
Cannot automatically launch internet programs	80
Solving software problems	81
Computer will not start up and the HP logo does not appear	81
“Illegal Operation has Occurred” error message is displayed	81
Computer Setup (F10) Utility	83
Using Computer Setup (F10) Utilities	83
Computer Setup—Main	84
Computer Setup—Security	87
Computer Setup—Advanced	91
POST error messages	99
POST numeric codes and text messages	99
Interpreting POST diagnostic front panel lights and audible codes	103
Password security and resetting CMOS	107
Changing a setup or power-on password	107
Deleting a setup or power-on password	108
Using HP PC Hardware Diagnostics	109
Using HP PC Hardware Diagnostics Windows (select products only)	110
Using an HP PC Hardware Diagnostics Windows hardware failure ID code	110
Accessing HP PC Hardware Diagnostics Windows	111
Accessing HP PC Hardware Diagnostics Windows from HP Help and Support	111
Accessing HP PC Hardware Diagnostics Windows from Support Assistant	111
Downloading HP PC Hardware Diagnostics Windows	112
Downloading the latest HP PC Hardware Diagnostics Windows version from HP	112
Downloading the HP PC Hardware Diagnostics Windows from the Microsoft Store	112
Downloading HP Hardware Diagnostics Windows by product name or number (select products only)	112
Installing HP PC Hardware Diagnostics Windows	112
Using HP PC Hardware Diagnostics UEFI	113
Using an HP PC Hardware Diagnostics UEFI hardware failure ID code	113
Starting HP PC Hardware Diagnostics UEFI	113
Downloading HP PC Hardware Diagnostics UEFI to a USB flash drive	114
Downloading the latest HP PC Hardware Diagnostics UEFI version	114
Downloading HP PC Hardware Diagnostics UEFI by product name or number (select products only)	114
Using Remote HP PC Hardware Diagnostics UEFI settings (select products only)	115
Downloading Remote HP PC Hardware Diagnostics UEFI	116
Downloading the latest Remote HP PC Hardware Diagnostics UEFI version	116
Downloading Remote HP PC Hardware Diagnostics UEFI by product name or number	116
Customizing Remote HP PC Hardware Diagnostics UEFI settings	116
Backing up, restoring, and recovering	117
Backing up information and creating recovery media	118
Using Windows tools for backing up	118
Using the HP Cloud Recovery Download Tool to create recovery media (select products only)	118
Restoring and recovering your system	119
Creating a system restore	119
Restoring and recovery methods	119
Recovering using HP Recovery media	119
Changing the computer boot order	120
Using HP Sure Recover (select products only)	120
Statement of memory volatility	121
Current BIOS steps	121
Nonvolatile memory usage	123
Questions and answers	125
Using HP Sure Start (select products only)	127
Power cord set requirements	129
General requirements	129
Japanese power cord requirements	129
Country-specific requirements	129
Specifications	131