PSU low voltages

[Peter]

Hi all,

I just got hold of a cheap Q-Tec 400watt PSU as part of a system build,
but fear I may have got a dud. When I placed my Geforce 5900XT graphics
card the first alarm bells started ringing as the card fan would not
spin up when starting the computer. It just flicked slightly and that
was that.

Anyway, it didn't stop the computer from working, but I was a little
worried so once I was able to install windows the first software I
wanted to include was some kind of voltage monitor. Anyway, I had a
copy of Aida32 and installed that and it's monitoring of both +5 and +5
standby lines give a reading of less than 4V. Somewhere around 3.8 to
be more precise. Would these readings be the reason why the fan on the
graphics card is not spinning and is Aida32 a worthwhile/accurate tool
for monitoring PSU voltages?

Also, since installing the Nvidia drivers for this card, just to confirm
my concerns, whenever the computer boots into windows I get an Nvidia
pop-up box saying there is insufficient power to the card and so it is
running at reduced spec.

Also the card fan still doesn't spin up, even once into windows and the
fan is ok, I think, because I placed it in a 2nd machine in which at
least the fan spun for a few seconds when powering up the computer,
before it stopped spinning. Obviously I was unable to check if it would
have worked once in windows as that would have involved removing drivers
for the current graphics card and installing the 5900 ones.

Cheers in advance

 

[Michael Hawes]

Hi all,

I just got hold of a cheap Q-Tec 400watt PSU as part of a system build,
but fear I may have got a dud. When I placed my Geforce 5900XT graphics
card the first alarm bells started ringing as the card fan would not
spin up when starting the computer. It just flicked slightly and that
was that.

Anyway, it didn't stop the computer from working, but I was a little
worried so once I was able to install windows the first software I
wanted to include was some kind of voltage monitor. Anyway, I had a
copy of Aida32 and installed that and it's monitoring of both +5 and +5
standby lines give a reading of less than 4V. Somewhere around 3.8 to
be more precise. Would these readings be the reason why the fan on the
graphics card is not spinning and is Aida32 a worthwhile/accurate tool
for monitoring PSU voltages?

Also, since installing the Nvidia drivers for this card, just to confirm
my concerns, whenever the computer boots into windows I get an Nvidia
pop-up box saying there is insufficient power to the card and so it is
running at reduced spec.

Also the card fan still doesn't spin up, even once into windows and the
fan is ok, I think, because I placed it in a 2nd machine in which at
least the fan spun for a few seconds when powering up the computer,
before it stopped spinning. Obviously I was unable to check if it would
have worked once in windows as that would have involved removing drivers
for the current graphics card and installing the 5900 ones.

Cheers in advance

You need to check volts with a meter.
Mike.

 

[Peter]

You need to check volts with a meter.
Mike.

Hmmm, was hoping that wouldn't be the case.
I have a meter but haven't a clue how to use it to do this kind of
thing. Got a link to a helpful site?

 

[larry moe 'n curly]

I just got hold of a cheap Q-Tec 400watt PSU
When I placed my Geforce 5900XT graphics card the
first alarm bells started ringing as the card fan
would not spin up when starting the computer.

Anyway, it didn't stop the computer from working, but I was a little
worried so once I was able to install windows the first software I
wanted to include was some kind of voltage monitor. Anyway, I had a
copy of Aida32 and installed that and it's monitoring of both +5 and +5
standby lines give a reading of less than 4V. Somewhere around 3.8

I get an Nvidia pop-up box saying there is insufficient power
to the card and so it is running at reduced spec.

What mobo and CPU do you have?

I remember seeing the inside of a 400W Q-tec, but the only Q-tec
internal picture I can find is of their 550W model:
www.bit-tech.net/images/review/123/7.jpg, and it looks one of my old
200W PSUs. If your mobo runs the CPU off the +5V rail (i.e., has no
square 4-pin connector with yellow wires on it), then maybe it's
putting too much of a load on the PSU's +5V and +3.3V.

I've learned not to trust voltage monitor readings at all, especially
after one said that my ECS K7VTA3 was putting out 10.6V on its +12V
rail and another said it alternated between 6V and 8V every second, but
all along the meter read a rock-steady +12.1V.

I'm cheap, but I won't use a junk PSU because they can be unreliable or
even damage the mobo and HD if they fail. Still, I haven't paid more
than $25 US for a PSU in the last 2-3 years, and that $25 included the
case. You may be able to find a rock solid
Fortron/Sparkle/Hi-Q/PowerQ/Powerman/Trend/Aopen PSU at a low price,
and their 350W models are more like the average major brand 400W.

 

[zero]

download this

http://www.almico.com/speedfan.php

screenshots

http://www.almico.com/sfscreenshots.php

ignore the fan stuff but it shows you all the volt stuff at the bottom

everyone will slag it and sya meter it but its good stuff

widely used in small format pc areas - shuttles foe instance to control the
fans as well

worth a shot !

 

[Peter]

What mobo and CPU do you have?

Gigabyte k7 Triton GA-7S748 with Athlon XP 2700+

I remember seeing the inside of a 400W Q-tec, but the only Q-tec
internal picture I can find is of their 550W model:
www.bit-tech.net/images/review/123/7.jpg, and it looks one of my old
200W PSUs. If your mobo runs the CPU off the +5V rail (i.e., has no
square 4-pin connector with yellow wires on it), then maybe it's
putting too much of a load on the PSU's +5V and +3.3V.

True, there is no 4 pin connector for the cpu

I've learned not to trust voltage monitor readings at all, especially
after one said that my ECS K7VTA3 was putting out 10.6V on its +12V
rail and another said it alternated between 6V and 8V every second, but
all along the meter read a rock-steady +12.1V.

I'm cheap, but I won't use a junk PSU because they can be unreliable or
even damage the mobo and HD if they fail. Still, I haven't paid more
than $25 US for a PSU in the last 2-3 years, and that $25 included the
case. You may be able to find a rock solid
Fortron/Sparkle/Hi-Q/PowerQ/Powerman/Trend/Aopen PSU at a low price,
and their 350W models are more like the average major brand 400W.

I have an old AGP X4/X8 card not in use that also has a (somewhat
smaller) fan attached and so am going to try that out to see if the fan
spins up on that. Also, when I used Aida32 on my other PC, that had
both +5 rails measured at about 4.8/4.9 for the 350W PSU so I may also
try swapping that one out because the g/fx card in that machine doesn't
have a fan attached (just a heatsink) and therefore may be able to make
do without the extra power required to drive a fan for now. Obviously
though, if the PSU is not up to spec, then I intend to return to the
local store where I purchased it and have it replaced.

 

[Peter]

download this

http://www.almico.com/speedfan.php

screenshots

http://www.almico.com/sfscreenshots.php

ignore the fan stuff but it shows you all the volt stuff at the bottom

everyone will slag it and sya meter it but its good stuff

widely used in small format pc areas - shuttles foe instance to control the
fans as well

worth a shot !

Cheers, have downloaded it and its readings on this (my stable machine)
are just the same as before, with both +5 rails reading at between 4.8
and 4.9V. Am now going to install on the nvidia card machine to see if
same readings.

 

[Peter]

Hi all,

I just got hold of a cheap Q-Tec 400watt PSU as part of a system build,
but fear I may have got a dud. When I placed my Geforce 5900XT graphics
card the first alarm bells started ringing as the card fan would not
spin up when starting the computer. It just flicked slightly and that
was that.

Anyway, it didn't stop the computer from working, but I was a little
worried so once I was able to install windows the first software I
wanted to include was some kind of voltage monitor. Anyway, I had a
copy of Aida32 and installed that and it's monitoring of both +5 and +5
standby lines give a reading of less than 4V. Somewhere around 3.8 to
be more precise. Would these readings be the reason why the fan on the
graphics card is not spinning and is Aida32 a worthwhile/accurate tool
for monitoring PSU voltages?

Also, since installing the Nvidia drivers for this card, just to confirm
my concerns, whenever the computer boots into windows I get an Nvidia
pop-up box saying there is insufficient power to the card and so it is
running at reduced spec.

Also the card fan still doesn't spin up, even once into windows and the
fan is ok, I think, because I placed it in a 2nd machine in which at
least the fan spun for a few seconds when powering up the computer,
before it stopped spinning. Obviously I was unable to check if it would
have worked once in windows as that would have involved removing drivers
for the current graphics card and installing the 5900 ones.

Cheers in advance

Thanks for everyone's help and advice, but I have resolved the problem.
The nvidia software that was displaying the error message was called
sentinal and as soon as I typed the words 'nvidia' and 'sentinal' into
google groups up popped someone who had a problem with their FX5900
card. Specifically that they had plugged the 'additional power
connector' into the card and the error message had gone. They went on to
say that this power connector was a spur from their HD power connector
so I took a closer look at my card and immediately discovered a standard
4-pin socket to accommodate the same power connector as used in HDs, CD
and DVD drives. Oops!!

What a prat you may think, but there is absolutely no reference to doing
this in the documentation that comes with the card. More than likely,
if I had read any readme's or additional docs that were included on the
Cd I would have come across it eventually, but it amazes me that this
wasn't in BOLD PRINT somewhere.

Apologies for wasting everyone's time on the Power Supply red-herring
and, btw, the fan is now spinning nicely and the error message has gone.