M2N68-LA motherboard 12vdc for the cpu fan is only 4vDC.

more info required year, make,model, are there any codes, has any work been done on vehicle lately,etc
All this info helps diagnose a fuel system problem
re post with this info to get your answer

Are you seeing this error on a system you built or a pre-built system? If it is a pre-built system, check that the fans are running. Next check where the fans are plugged in, the CPU fan must be connected to the CPU fan connector on your motherboard. The chassis (rear case fan) only needs to be connected to the motherboard if you want the monitoring/PWM (modulated fan speed) option. If your CPU fan is powered directly from the power supply, change this.

If this is a system you built or recently updated the case, check your fan power connections, as above. Next check the fan speed. My ASUS board will give the "CPU fan not detected" error if the CPU fan speed is too slow. A different CPU fan will solve the problem. (I got my fan with the CPU; it works fine.)

I hope this helps. Please add a comment with more information about your system for more assistance.

Cindy Wells

you posted a mobo number not a PC real name.
its HP 412410-003 HP 442031-001 S775 A/V M/B
that is XW4400 ( I own a mint xw4600 ) simular.
why post MOBO #'s and not true PC name?????????

no MOBO works ever with all memory out , why do that?
just to hear the 4 beeps the manual on the PC
its a HPE workstation in fact not a PC.
the PSU is dead. (or a gross short)
why not test the PSU First with the jumper clip
im reading your manual for you now XW4400
it says. BAD PSU.

Blinks red 4 times (once per
second), then a 2-second
pause, and then 4 beeps


the fans slow means 12vdc is weak as in not at 12vdc.
only 2 things cause that.
bad PSU, or the 12vdc bus is shortred.

more sure
5 beeps is memory dead, low bank.
6 is video bad. GPU card.

the beep code 4 is top priory error
think about that, if power is bad, all else IS
in electronics power is first. and always first.
means at spec.


the test is easy and 3 fold is savvy
1: the jumper test.
http://www.pcdied.com/power.html#rapid_testing
2: same as above, but turns on and voltage test all pins.
3: if really pro- a load bank test, puts full load on PSU.

that is why shops with tools waste little time.

strip all things off the MOBO
memory
all drives
all PCI cards and express cards. (all but CPU) CPU dont fail
if the heatsink has not fallen off.
remove all things that can short out 12vdc, fans and drives.
do not run it with fans pulled for more than say 15 seconds
use a voltmeter, turn it on
measure 5v and 12v and 3.3v psu pins. seen in link above
a dmm meter is $20 at warfart. anyone can use one, easy.
the black wires are ground (common) meter black to black.
red meter to the 3 top power pins on PSU jack.


now my wild guess, bad PSU. but I cant strip your PC nor watch you.

"i can find my dmm?" did you mean CAN'T?
"its clearly off", what is off?
the fans are 3 pins,2 are power, one is RPM tachometer.
"it all works fine", so you can boot and run any OS, ?

"the voltage reads +12vdc", where, at fan or PSU?
the fans run off 12vdc, they are DC motors (from outside fan)
if the fan runs slow at 12vdc the the fan is bad or is a low RPM
fan, as some are, bigger fans run slow, for less noise.!

first is the CPU fan it must run full speed, if not the CPU will overheat in seconds and ALL CPU shut them selves (by there selves) this way. so CPU fan is first. what does it do... there....?

then BIOS screens. GOT BIOS UP? and running? with, ESC key pressed>.
let me guess your symptoms
1: PC dead. will not boot.
2: BIOS dead.
3: all fans DEAD,.
4: power switch works and all PSU voltages read right, (seems not)/?
5: if the PSU power wire reads right(DMM), matching the side sticker voltages, and the CPU is dead, the MOBO is dead, or CPU is toasted.


here is a modern PSU, sticker.
see 5 to 10 power lines, see them. all must read correctly
if a fan is dead, then its dead if 12vdc is present on the fan power pins.

Motherboard fan connectors typically use a small 3-pin which looks like this:
the left connector is a female connection (the side with 3 holes) the middle and right are male connections, has 3 metal pins:

• Black: GND (ground)
• Red: +12VDC or +5VDC (12V or 5V DC - direct current)
• Yellow: Tachometer signal (used to read fan speeds)

NOTE: Wire color may vary, and some fans or motherboards may control fan-speed.

Some fans use a 4-pin connection, which is generally a CPU fan connector but not always:

This pictures a 4-pin connection, but may look different from other 4-pin connections because the wires are covered in a black sleeve, which keeps them safe from harm and to reduce potential negative affects on airflow created when there are lots of loose wires inside a computer case.


This photo shows a 4-pin connection attached to a motherboard next to a 3-pin connection in a motherboard. While it is not recommended in the case of the CPU's fan, in the case of other internal case fans with a 4-pin connection, it is possible to plug them into a 3-pin connector of the motherboard, but the ability to control fan speed, which is controlled in the 4th pin will be lost.

Though sometimes computers have a way of controlling fan speed on a 3-pin or 4-pin connection even without the 4th pin, such *** voltage regulation and reading tach. feedback. These things are typically things a general user doesn't need to worry about unless their computer is running particularly hot and causing trouble.

In which case, it might be worth investing some money in a fan controller, which takes a power connection, several fan connections (varies based on the controller you get) and gives you the ability to control fan speed externally on your computer case. My controller has nice dial knobs, though some "fancy" controllers have a display and up and down buttons. (Fan controllers would be at your own discretion in terms of price, you can get them cheap all the way up to seemingly ridiculous expensive)

In the event of not having enough 3pin or 4pin connections on a motherboard, it is still possible to add case fans by way of 4pin molex connections:

A female molex connection


A male molex connection

Some case fans run exclusively through these connectors, others have a combination of a 3pin (or 4pin possibly, though I've never seen this combination) and a 4pin molex connector. In this case, the molex connector can connect directly to a cord from the power supply and run the fan. It is possible to run case fans without having them connect to the motherboard at all! Which makes it possible to connect more fans, with less available connections for your fans on your motherboard.

If a fan is a certain connection (any of the 3) and you need to convert it, for example:

• a 3pin to a 4pin molex because your motherboard doesn't have enough 3pin connectors for all your fans,
  

adapters are available to change one type of connection to another, at many online retailers (such as newegg.com, amazon.com, or other electronic supply retailers) and some retail stores, Best buy might have something, though you'd have a safer bet at a store like Micro Center which is more specialized for PC building or an alternative PC/electronic store.

To ensure you solve your problem, just be sure to familiarize yourself with the motherboard you are planning on buying (or have) and the fans you plan to have inside your computer. It can be a bit more work to check the specs on the fans and motherboards, but a little work saves hours of headache later.

Yes, it will work, just that the fan control will be missing and the fan will run at full speed constantly.

no PC stated, must we guess all that?

there are 2 causes,, (3?) fans dead, even inside PSU?????
1: bad PSU
2: the motherboard or all modules connected can short and bingo.
3: power switch cable fell off?


a desk top has 2 to 3 fans or more.
PSU
CPU
GPU
case.

at least the first 2 are there and MUST SPIN
if not 12vdc is DEAD.

U'L LDAMAGE YOUR MOTHERBOARD AND THE CPU TURN IT OFF AND UNPLUG ALL CABLES OPEN THE CAS COVER AND CHECK THE CPU FA N IS MOVING OR NOT IF NOT THEN CLEAN THE FAN AND CHECK THE FAN CABLE IF IT STILL NOT MOVING CHANGE THE HEATSINK INCLUDIN THE FAN DA VN

installed the right tail light assembly

I suggest replacing the fans with new fans. Fans do expire and they need to be replaced.