What are the symptoms of an underpowered or weak power supply?

  • Thread starter Thread starter Mac Cool
  • Start date Start date
What are the symptoms of an underpowered or weak power supply?

You find yourself posting lots of queries on this newsgroup!

Seriously, I've only got personal experience of two situations
where an under-power psu was at fault:

1) Me, about 2 years ago. Cheap case that came with an even cheaper
psu. When I upgraded to a 1900+ athlon, stuck in a dvd and 2nd hd
(I know, Iknow), I suffered random lockups. Sought help here, took
the advice I was given, and dropped in a decent 350w PSU. Problem
solved.

2) A friend of mine rjust now. New build wouldn't boot properly from
the power switch - he'd switch it on, it wouldn't even post. Then if
he hit the reset button it would boot normally. I surmised that the
(dirt-cheap) psu couldn't supply the juice to power up the board, ram
graphics, ram etc *and* spin up all the drives for post. I passed on
the 350w psu, since it was now a spare, and his machine boots fine.

Best,

Vic.
 
Vic. said:
You find yourself posting lots of queries on this newsgroup!
Click to expand...

Here is what is going on... I replaced the DVD drive with a DVD burner,
then my 2.5 y.o. hard drive went bad, the replacement hard drive went bad
within 30 days, the new replacement drive is fine (so far) but now my 2
y.o. backup drive is going bad (the backup drive and the original hard
drive are the same model, so it could be that). My monitor has started
blinking and sometimes my computer just slows down like a turtle on
Quaaludes. I'm wondering if it's just old age or if the power supply could
be killing the hard drives.

Besides the DVD burner I added a GeforceFX 5900XT which requires
additional power. The power supply is a 250W Foxteq and I'm wondering if
it's struggling.
 
That's a good one. Also random (windows will fail to load). In severe
cases, random unexpected shutdowns. -Dave
Click to expand...
Expect crashes, hangs and overall slow performance, especiallly during
heavy computing loads.(I had one mini-tower with a puny 185 watt
supply. When I installed a newer Nvidia video card the whole system
kinda "browned" out. The drive ground to a halt and all the lights
went out. Installed a 450 watt supply and it ran fine after.)
 
Here is what is going on... I replaced the DVD drive with a DVD burner,
then my 2.5 y.o. hard drive went bad, the replacement hard drive went bad
within 30 days, the new replacement drive is fine (so far) but now my 2
y.o. backup drive is going bad (the backup drive and the original hard
drive are the same model, so it could be that). My monitor has started
blinking and sometimes my computer just slows down like a turtle on
Quaaludes. I'm wondering if it's just old age or if the power supply could
be killing the hard drives.

Besides the DVD burner I added a GeforceFX 5900XT which requires
additional power. The power supply is a 250W Foxteq and I'm wondering if
it's struggling.
Click to expand...

You didnt say what processor you run, but guestimating for fairly
recent system:

Athlon XP's in the 1800-2100 range ~ 90 watts
(slightly higher for a P4, but we *are* guestimating!)
FX5900XT ~ 70-80 watts,
Motherboard ~ 25 watts
DVD ~ 20 watts

GRAND TOTAL = 215 watts, before you add in HD's, fans etc.

On the basis of these numbers, I'd say your psu was pretty marginal.

The psu might not be the source of all your woes, but if your
processor load is comparable to the figure I used above, it won't harm
your system to put a quality 350 watt supply in your rig.

If it doesn't do any good you can curse me to hell and back: I shan't
blush!

Best,

Vic.
 
You didnt say what processor you run, but guestimating for fairly
recent system:

Athlon XP's in the 1800-2100 range ~ 90 watts
(slightly higher for a P4, but we *are* guestimating!)
FX5900XT ~ 70-80 watts,
Motherboard ~ 25 watts
DVD ~ 20 watts

GRAND TOTAL = 215 watts, before you add in HD's, fans etc.

On the basis of these numbers, I'd say your psu was pretty marginal.
Click to expand...

I just installed a couple FX5900XT cards. Both say 300W power supply is
MINIMUM system requirement. -Dave
 
I just installed a couple FX5900XT cards. Both say 300W power supply is
MINIMUM system requirement. -Dave
Click to expand...

It's a sensible requirement. The manufacturers don't want to be
saddled with returns due to pre-existing power supplies which
are not up to the job:

"My machine ran *fine* until I installed this shitty card!" etc.

[Recent mid to high-end cards can be absolute hogs - IIRC, the 6800
ultra pulls in excess of 100w all on its lonesome. Ouch.]

If you add up *all* of the OP's component power requirements, I bet
you'd be pretty close to the supposed 250w capability of his power
supply. Of course, these 250 watts are split across all of the various
rails, and there's a good chance one of these is hitting the buffers
and his machine is misbehaving. I'd say it's likely that if the OP
spends the bucks and drops in, say, an Antec TruPower 380 or suchlike,
he/she'll have a good 100+w in reserve, all rails will stay within
limits and the machine will run sweetly.

Vic.
 
The cheap power supply I got with my ATX case a while back had a bad
3.3V channel (that showed up fine on hardware probes), and it caused
random beeping whenever I used a graphically-rich program (such as
any computer game made less than three years ago), but didn't hinder
performance at all. After checking my graphics card settings and
replacing the card itself (after giving the store I bought it at an
earful), I replaced the power supply and it worked great.

==============
Posted through www.HowToFixComputers.com/bb - free access to hardware troubleshooting newsgroups.
 
Back
Top