NF7-S / blew another PS unit

So many NF7's or people that don't know how to use them?

W-Tom

The system in question has a TTGI (rated) 450W- PS
I believe it is the type everyone should avoid as you have pointed out, and,
I have experienced.
I have a couple of new Topower units (rated over 500, I'll have to look) and
one new Enermax 550 sitting around.
Now that I have rid myself of all the TTGI's in this place, It's time to
step things up a bit.
Curiously, there doesn't seem to be any damage to the components within the
system ...
I just came home and the system was "on" but not booting to Windows. (twice
this happened)

Thanks

...

DDDD

Probably becasue they are so popular.
I have these two machines and two others.
All are equiped with Abit's NF7-S
Needless to say they are like race cars, so there is a pile of spare parts
sitting in the closet :-)
The system in question is the only one I'm having trouble with.
The remaining systems are running fine.

...

It's bang for buck the best overclocking board out there, most people
down here overclock - running everything ' on-the-edge ' results in
problems and instability, hence the amount of posts.

BoroLad

When lighting hits a house that's it. It finds a way to ground. It doesn't
keep
running through the house. The initial strike might damage a computer, but
if
it were hit with a good jolt you would know it for sure. If it was a minor
spike your APC should filter it out if that model has that feature.

I'm going to check the recepticle and APC today ...
Last night I switched the APC's and the machine I'm working on now seems
faster than usual.

...

A little off subject, but I see a lot of problems being reported with the
NF7 motherboard on the forum. Is this because the board is basically bad or
is it just because there are so many of them out there?

DDDD

...

Don't know what that power supply is. However many power
supplies are dumped into N America because so many computer
experts don't even have basic electrical knowledge. A
computer power supply must have a long list of essential
functions and typically costs about $60 full retail. To sell
power supplies at $25 and $40, those essential functions are
conveniently forgotten.

For example, all DC outputs from any standard power supply
can be shorted together - and still the power supply is not
damaged. Intel specs even define how heavy that shorting wire
must be. And yet many 'dumped into N America' power supplies
will self-destruct if shorted. This is totally unacceptable
(as is the idea that a heavily loaded supply will be
overstressed).

At 450 watts, you probably would have about twice the power
necessary for that system. However many dumped supplies claim
power ratings they cannot even meet:
#

A quality supply will provide a long list of numerical
specs. An abridged list:
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

But if dumping a power supply, then best not to provide any
usch information. After all the supply is being sold to one
who only cares about one specification - the price.

Is that APC a battery backup power supply? If so, then it
connects comptuer directly to AC mains when not in battery
backup mode. IOW hundreds of consecutive surges would pass
through UPS directly into computer before that UPS could even
consider switching to battery backup mode. It does not claim
to provide protection from the type of surge that typically
causes damage. It does claim protection from a type of surge
that typically does not exist. Enough for many to *assume* it
protects from all types of surges.

Electric motors typically are not damaged by surges. Was it
electric motors that failed? Currently there is too little
solid facts to say why so much has failed. Do you have light
bulbs often glowing brighter or dimmer?

Power supplies are suppose to be rated to withstand voltages
up to 1000 volts. The dead body is always the best evidence.
What failed inside the power supply - a necessary fact to
obtain useful answers here.

Well no wonder. Is this your supply 450W PS - TTGI and how much did it cost?

Those hard drives alone when you first turn the system on draw a lot of current
on the 12+ volt line I believe for spinup as do the the CD drives and you have
seven of them. That could be the problem right there. The current lowers after
they get up to speed, but that initial current draw might be killing your
supplies.

Some supplies have an internal fuse that could have blown inside the supply. If
your very careful you could open the supply to check for a blown fuse. Even
with the power supply not plugged in you can get an leathal electrical shock
from capacitors inside unless they are discharged. So open the supply at your
own risk.

HAL9000

(Writting from another system)

Abit NF7-S (V2)
BIOS - 19
Windows 2000
AMD 2400 Barton
(3) 512MB / PC 2100 / Non ECC - Crucial
(1) 80GB HD - Maxtor (OS only)
(1) 80GB HD - Maxtor (Programs only)
(1) 80GB HD - Maxtor (Data only)
(1) 200GB HD - Maxtor (Remote - data only)
BFG 5950 FX video
450W PS - TTGI
DVD RW
CD RW
CD ROM
40 GB Tape
750 Zip
Floppy / Multi card reader
APC 700LS back up
KVM switched keyboard, mouse and monitor to second system (which works fine)

I think that's it

...

Are you using a cheap power supply each time?

Could you describe your system? Including power supply wattage,
brand, cpu speed, cpu voltage, and overclocking?

Forrest

Motherboard Help By HAL web site:
#

On Wed, 04 Aug 2004 20:10:39 GMT, "Dreamer.nian2"

Oh yes ...
The power receptacle is a GFCI ...
So far, I haven't had a problem with it.
The house circuit is 120v with a 20 amp circuit
PS's are set on 115v
two PCs running, 1 monitor, that's it.
No toaster or fridge ...

...

The system is on an APC 700LS
If it were to spike, I would think the back up would assist..

...

Rather than looking at the board or PSU as the possible cause have you
considered the mains supply? Unless you have a surge protector fitted
could you be sure that the mains voltage does not have any spikes that could
be the cause of your problems..?

I assume that you are using a different lead to connect the mains to the PSU
and even a different power outlet to, not much use though if you are having
mains voltage fluctuations or spikes.

AFAIK, apart from an internal fuse there is little to repair in a PSU.
BUT be very careful if you decide to open it up as the large capacitors can
hold sufficient electricity for sometime after it has been disconnected from
the main supply to be really dangerous.

--
Regards

Morgan

Hard drive noisy
#