Determine power requirements system... possible problem with power supply?

Hello ng,

I was wondering if anyone could help me fix a new problem that`s come up.

While my computer is on, there is a noise coming from it... I usually have
problems like that, which are almost impossible to explain to others and
therefore hard to fix. I`ll give it my best shot. Lasting for a total of 8
seconds, I hear a sort of resonance which builds in strength gradually,
then drops. A new period of 8 seconds starts, again building up from zero
to annoyingly audible. I have spent a lot of money making my computer
ultra-silent, so the effect is pretty bad.
The sound seems to have no relation with the amount of work load I put my
computer through. It makes no difference whether the computer is idle
or doing heavy encoding duties or something. When booting the noise is
really quite loud and constant for a couple of seconds, soon afterwards
the cycles starts. There is no difference whether the computer has been
off for a few seconds or a few hours.

Recently, there have been 2 computer related changes. First, I switched
from cable internet access to ADSL internet access. This can hardly affect
my system, as the modem was connected in both cases to my router and it
couldn`t care less where the connection is coming from. My second change
has been replacing a P-ATA 30 GB IBM Deskstar GXP75 harddisk with a P-ATA
Hitachi 7K250 250 GB harddisk. Other than these two changes, nothing has
changed. The problem came up `suddenly`. And it won`t go away.

Due to the position my computer is in (it is hard to reach), it is really
difficult to have my computer running and physically checking what`s going
on. However, if I were to judge where the sound is coming from, I would
say it`s coming from the upper part of the tower. The most likely suspect
is therefore my power supply.

I`m running an ultra-quiet Lexus power supply, 300 watt. It is less than a
year old. Perhaps it cannot supply enough power to the system or
something, so I would like to determine the power requirements of my
system. Can anyone tell me how I could make an educated guess in this
matter? Or, look at my specs and take a guess yourself.

Case: AOpen Miditower ATX HQ45AP
Power supply: Nexus NX-3000 (replaced the AOpen power supply) 300 watt
Motherboard: MSI K7T Turbo 2 Limited Edition Processor: AMD Athlon XP
1800+
Proc.Cooler: not certain, I think it`s the Nexus KCZ-2700 LS Harddisk 1:
Seagate Barricuda 7200.7 80 GB (ST380011A) Harddisk 2: Hitachi 7K250 250
GB
DVD-ROM: Toshiba SD-M1802 16x
CD-RW: Lite-on LTR-52246S 52x 24x 52x Diskdrive: Sony 3,5" Diskdrive
1.44Mb Graphics card: 3D Blaster 4 Titanium 4400 (nVidia GeForce4 4400 128
MB) (REMARK: took off the noisy power supply, replaced by Zalman ZM80C-HP
heatpipe passive cooling solution)
Memory: 768 MB SDRAM
Soundcard: Terratex DMX X-Fire 1024 4.1 Controller card: USB 2.0 Speakers:
Creative PCWorks FourPointSurround 1500 Network card: Sitecom PCI Fast
Ethernet card 10/100 Mbit Router: Sitecom DC-202 Trackball: Logitech
Marble Mouse USB
Mouse: Logitech Cordless Mouseman Wheel USB Tablet: Wacom Graphire 1 USB
Keyboard: Logitech Internet Keyboard (serial) Scanner: Canon CanoScan
N670U USB
Printer: HP DeskJet 720C LPT2
CRT monitor: Iiyama Diamondtron A705MT Vision Master Pro411 17" TFT
monitor: Dell 1504FP 15"

I`ve included all peripherals which are powered on when using the system.
I welcome any suggestions!

Regards,
Willem

 

350 watt is bare minimum these days.
get the highest u can afford

 

Well actually, I wasn`t looking to replace my power supply... like I
said, the above system used to work fine. I need to be certain that
the problem is the power supply and if it is, if the problem is a too
demanding system. If so I will of course get a more powerful one.

Oddly enough the system seems to be doing fine at the moment. I have
opened the case and made sure that all cables are routed correctly, might
have moved a bunch when installing the new harddisk. Right now it`s all
peace and quietness, but I`m not sure it is going to last.

Regards,
Willem

 

Appologies for the earlier reply. Need new glasses or possibly less alcohol
in my blood stream lol
It could possibly be the cpu fan.
Can u get you pc out with 1 power cable then you can test it.
I also suggest getting hold of a can of compressed air. Most computer shops
stock them.
Give the CPU fan a good blast. make sure you stop the fan from spinning
while you spray as it can damage it.
Clean all the fins on the fan and give all the fins on the heatsink a good
blast to.
I would not suggest taking the psu apart due to the extreme voltages even if
the power is not plugged in.
If you can, give the PSU fans a good blast to. put something plastic through
the fan grill to stop the fan spinning when u spray it.

Swiss T

p.s If you can, try and move the ide cables out the way to improve airflow.

 

Get a nice small smooth paint brush and brush off/poke the fans etc once every few
months.
I take fans off every now and again (Video and CPU) and give them a thorough clean.
The bigger fans can be dealt with in situ.
If you really wanna clean out/dismantle the PSU then power down but leave connected
to the AC mains with power switch off this will allow the earth to discharge the
capacitors although some countries with 120 VAC don't have earths in which case
totally remove power and leave for 10 mins to allow the capacitors to discharge.