P4 Asus : CPU Fan and PSU Fan not spinning

H

hariramasubbu

Hi all ,

Please help me out .

Connected 20 pin and 12V Power supply cables to MoBo
Connected CPU fan to the righ socket in MoBo
Switch on PSU
Nothing happens. CPU and PSU fan not spinning.
Green LED light in MoBo lightsup meaning there is power in MoBo.

Tested power supply, actually works with another MoBo
Tested CPU Fan, works with another MoBo

Processor:Intel P4 processor
Mobo:ASUS p4S800D-X
EnerMax 350W power supply in ATX case.

What am i doing wrong.

Thanks
Hari
 
S

Simon

Hi all ,

Please help me out .

Connected 20 pin and 12V Power supply cables to MoBo
Connected CPU fan to the righ socket in MoBo
Switch on PSU
Nothing happens. CPU and PSU fan not spinning.
Green LED light in MoBo lightsup meaning there is power in MoBo.

Tested power supply, actually works with another MoBo
Tested CPU Fan, works with another MoBo

Processor:Intel P4 processor
Mobo:ASUS p4S800D-X
EnerMax 350W power supply in ATX case.

What am i doing wrong.

Thanks
Hari
You did connect the power switch from the case to the mobo didn't you ?
 
W

w_tom

It is a power supply 'system'. Which component is bad? Where do
you look? Others will wildly recommend 'try this and try that'- also
called shotgunning. But a decisive answer means one minute probing
inside the case and numbers from that 3.5 digit multimeter. Without a
meter, others will have you disconnect this, replace that, ...
shotugnning. Little is learned only from observation. Get the 3.5
digit multimeter. Find out what is defective before replacing anything.

Start by taking voltage of the purple wire (from power supply to
motherboard) when computer is connected to wall receptacle but not
powered on. Then take voltage numbers from green and gray wire before
and when power switch is pressed. Those numbers will elicit useful
replies.
 
C

Conor

It is a power supply 'system'. Which component is bad? Where do
you look? Others will wildly recommend 'try this and try that'- also
called shotgunning. But a decisive answer means one minute probing
inside the case and numbers from that 3.5 digit multimeter. Without a
meter, others will have you disconnect this, replace that, ...
shotugnning. Little is learned only from observation. Get the 3.5
digit multimeter. Find out what is defective before replacing anything.
There's a reason people suggest try this and try that. It's because
99.9999999% of PC users have no clue about electronics and are more
likely to **** something up with a DVM than find out what's not working
so making sure it's all connected properly is a good step.

So next time before you go suggesting something apt to an electronics
engineer, perhaps you should think about the target audience.
 
W

w_tom

The meter is so ubiquitous as to be sold in Sears, K-mart, Home
Depot, Wal-mart, Lowes, and Radio Shack. A tool little more complex
than an Ipod. Yes, some people are too dumb to learn how to use an
Ipod. But then those same people should not be fixing a computer.

Those who make computer repair complicated and expensive do as Conor
recommends. Those who want solutions identified in but minutes get the
meter. A device so complicated that only the more intelligent among us
who therefore shop at Walmart can use a meter.

Conor - stop trying to scare everyone only because simple tools scare
you.

Meanwhile a simplest solution starts by taking voltage of the purple
wire (from power supply to motherboard) when computer is connected to
wall receptacle but not powered on. Then take voltage numbers from
green and gray wire before and when power switch is pressed. Those
numbers will elicit useful replies.

The target audience is not Conor. Reading numbers from a magic box
can only be performed by electrical engineers and geniuses who also
know how to use Ipods.
 
C

Conor

The meter is so ubiquitous as to be sold in Sears, K-mart, Home
Depot, Wal-mart, Lowes, and Radio Shack. A tool little more complex
than an Ipod. Yes, some people are too dumb to learn how to use an
Ipod. But then those same people should not be fixing a computer.

Those who make computer repair complicated and expensive do as Conor
recommends. Those who want solutions identified in but minutes get the
meter. A device so complicated that only the more intelligent among us
who therefore shop at Walmart can use a meter.

Conor - stop trying to scare everyone only because simple tools scare
you.
Bollocks. I did an BTEC electronics engineering course (one level below
Uni degree) and spent a good few years as a bench engineer working in a
sector that scrubbed IC numbers off components to prevent piracy.
 
H

hariramasubbu

Hi All

Thanks for all your suggestions. I tried replacing the power supply, a
new case, a new mother board and new 755 Pentium processor, all at
once. I still have the problem where , when i connect the 20 pin and
12v, i dont see the fan spiniing. I green led in motherboard is lit.

I switch on the system from the back side, the psu switch and not from
the front panel of the cpu.

What am i doing wrong.
 
W

w_tom

Thanks for all your suggestions. I tried replacing the power supply, a
new case, a new mother board and new 755 Pentium processor, all at
once. I still have the problem where , when i connect the 20 pin and
12v, i dont see the fan spiniing. I green led in motherboard is lit.

I switch on the system from the back side, the psu switch and not from
the front panel of the cpu.

What am i doing wrong.

You are shotgunning. You have not provided information that can
provide a useful response.

For example, the green LED is illuminated. That says electricity is
inside the machine. Is voltage sufficient? No one can say. Are other
voltages sufficient? Not even possible to speculate. Is power supply
controller properly connected and working? Impossible to say.

Again, simplest solution starts by taking voltage of the purple wire
(from power supply to motherboard) when computer is connected to wall
receptacle but not powered on. Then take voltage numbers from green
and gray wire before and when front panel power switch is pressed.
Those numbers will elicit useful replies.
 
H

hariramasubbu

Thanks for all your advice w_tom.

I fixed it. My bad.

I was just turning on the power button on the back of the pc(psu).
I should have connected the power switch to MoBo and switched on from
front side.

Thanks
 

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