Faulty psu, fan or mobo?

[Blink]

Archived from groups: alt.comp.hardware.homebuilt (More info?)

I've been getting loud cracking noises from a 2 momths old Enlight
200W psu. It replaced another, 3 years old, Enlight psu which had
developed the same problem.

My cpu fan has become rather noisy over time and noticeably speeds up
and down. The BIOS PC health monitor shows that the 12V core voltage
supply to this fan fluctuates between 11.42 and 11.54V, with the fan
speed fluctuating between 5600 and 5900 rpm.

Could this be causing a short in the psu, and if so, is it a fault in
the motherboard's voltage regulation or a fault in the fan causing the
voltage drop?

Any advice gratefully received.

 

[Stephen]

Archived from groups: alt.comp.hardware.homebuilt (More info?)

On Fri, 04 Jun 2004 20:15:04 +0100, blink <blink@eegah.com> tortured a
bunch of electrons for some unknown reason:

>I've been getting loud cracking noises from a 2 momths old Enlight
>200W psu. It replaced another, 3 years old, Enlight psu which had
>developed the same problem.
>
>My cpu fan has become rather noisy over time and noticeably speeds up
>and down. The BIOS PC health monitor shows that the 12V core voltage
>supply to this fan fluctuates between 11.42 and 11.54V, with the fan
>speed fluctuating between 5600 and 5900 rpm.
>
>Could this be causing a short in the psu, and if so, is it a fault in
>the motherboard's voltage regulation or a fault in the fan causing the
>voltage drop?
>
>Any advice gratefully received.

Replace the failing power supply.

Stephen


--

 

[Philo]

Archived from groups: alt.comp.hardware.homebuilt (More info?)

> Replace the failing power supply.
>

and also replace the cpu fan...

 

[Blink]

Archived from groups: alt.comp.hardware.homebuilt (More info?)

"Steven" wrote:
>> Replace the failing power supply.

"philo" wrote:
>and also replace the cpu fan...

Thanks. Strangely coincedental that 2 psu's show exactly the same
symptoms though?

 

[Guest]

Archived from groups: alt.comp.hardware.homebuilt (More info?)

Until numbers are obtained with a valid voltage measurement
device, then everything after that is simply wild
speculation. That motherboard monitor is just that - a
monitor. It does not provide numbers in sufficient accuracy.
Use a 3.5 digit multimeter to obtain voltages on wires from
PSU to motherboard. Especially important are voltages on red,
yellow, and orange wires. Currently your 12 volt number from
the monitor says power supply maybe defective.

So many computer experts without electrical knowledge means
N America is ripe for dumping inferior power supplies. Too
many supplies in clone computers do not even contain functions
considered necessary even 30 years ago and currently demanded
by Intel specs. Properly constructed supplies cost at least
$65 retail.

How to sell power supplies cheaper? Forget to include
essential functions. After all, those supplies target the
bean counters among us - people who cannot be bothered to
first learn the underlying science. Sell supplies under many
names. Don't provide a list of technical specs since such
supplies are then recommended only by the technically naive.
Last sentence tells much. At minimum, a supply should claim,
in writing, to meet these and many other requirements. Notice
real specs are provided with technical numbers:
Specification compliance: ATX 2.03 & ATX12V v1.1
Acoustics noise 25.8dBA typical at 70w, 30cm
Short circuit protection on all outputs
Over voltage protection
Over power protection
100% hi-pot test
100% burn in, high temperature cycled on/off
PFC harmonics compliance: EN61000-3-2 + A1 + A2
EMI/RFI compliance: CE, CISPR22 & FCC part 15 class B
Safety compliance: VDE, TUV, D, N, S, Fi, UL, C-UL & CB
Hold up time, full load: 16ms. typical
Efficiency; 100-120VAC and full range: >65%
Dielectric withstand, input to frame/ground: 1800VAC, 1sec.
Dielectric withstand, input to output: 1800VAC, 1sec.
Ripple/noise: 1%
MTBF, full load @ 25°C amb.: >100k hrs

Bottom line - until numbers are provided (both from
multimeter and manufacturer specifications), then no
responsible answer can be provided.

blink wrote:
> I've been getting loud cracking noises from a 2 momths old Enlight
> 200W psu. It replaced another, 3 years old, Enlight psu which had
> developed the same problem.
>
> My cpu fan has become rather noisy over time and noticeably speeds up
> and down. The BIOS PC health monitor shows that the 12V core voltage
> supply to this fan fluctuates between 11.42 and 11.54V, with the fan
> speed fluctuating between 5600 and 5900 rpm.
>
> Could this be causing a short in the psu, and if so, is it a fault
> in the motherboard's voltage regulation or a fault in the fan
> causing the voltage drop?
>
> Any advice gratefully received.

 

[Stephen]

Archived from groups: alt.comp.hardware.homebuilt (More info?)

On Sun, 06 Jun 2004 03:33:51 +0100, blink <blink@eegah.com> tortured a
bunch of electrons for some unknown reason:

>
>
>"Steven" wrote:
>>> Replace the failing power supply.
>
> "philo" wrote:
>>and also replace the cpu fan...
>
>Thanks. Strangely coincedental that 2 psu's show exactly the same
>symptoms though?

No, just unlucky. You did say they were the same cheap brand.

Stephen

--

 

[Guest]

Archived from groups: alt.comp.hardware.homebuilt (More info?)

On Sun, 06 Jun 2004 03:33:51 +0100, blink <blink@eegah.com> wrote:

>
>
>"Steven" wrote:
>>> Replace the failing power supply.
>
> "philo" wrote:
>>and also replace the cpu fan...
>
>Thanks. Strangely coincedental that 2 psu's show exactly the same
>symptoms though?

Is there some reason you use 200W PSU?
Is this a small proprietary chassis or mATX, such that a normal, full PS2
size and wattage unit won't fit?