Is Power Supply Underpowered? 1

[clickster]

We ordered 450 or so identical desktop PCs (small form factor). The power supplies keep going out on them and I think that it is because they are underpowered, but am not knowledgeable enough to decipher the readings on the PS label to figure out what I need to know. Can anyone explain this to me? I have listed the information from the side of the PS below. These power supplies are being used in P4 2.4 GHz machines with everything onboard/no cards. Simple logic tells me that 200W is way too low, but I need more than "what I wouldn't do...". According to Intel's website, P4 PC need a minimum of 250W PSs, but the manufacturer says that they are fine because they use the correct amperage per pin. Again, I'm not knowledgeable with electricity, so please keep it on my level. The more explanation/detail, the better. Also, I can't seem to get 200W when I do the math. I get much higher, probably doing something wrong. Thanks.

AC Input: 50-60 Hz
~100-127V,5A
~200-240V,3A
DC Output: 200W Max.

Red: +5V 15A
Orange: +3.3V 16.7A
(Red and Orange are 125W Max. according to the label)
Yellow: +12V 10A
(The 3 combined are 185W Max. according to the label)

Blue: -12V .3A
White: -5V .1A
Purple: +5VSB 2A
Gray: Power Good
Green: R/C

 

[1101001100110101]

Yes those are very weak Power Supply the max output is only 200W that's not going to cut it for a computer now a days. I wouldnt go any lower then 300W. Unfortunitly allot of pc makers cut corners on the PS and try to get away with the min they can.

 

[1101001100110101]

Oh and tell the manufacture he is full of it . Yea it supplies the right amprage to the pin. But, it doesnt supply enough total wattage when all the devices are pulling juice.

 

[clickster]

Do the numbers add up correctly for a 200W power supply? I'm not sure which cable colors to add together, etc. I keep getting somewhere in the high 260s, but I may be doing something wrong.

 

[1101001100110101]

This site is out dated but it gives you a rough idea of whats needed. You probabley have to pick the closest match.

http://www.jscustompcs.com/power_supply/

 

[1101001100110101]

I get 130 watts for the Red and Orange and 120 watts for the yellow so 250 total. If that's what your asking.

 

[clickster]

Yes. So what happens if the PC tries to draw max on those two when the max indicated is 185W?

 

[franklin97355]

The max allowed is 185W but you can draw it in any combination as long as you don't exceed any other of the max ratings.

 

[Freestone]

Fuzzy math:

3 combined are 185W Max + (-12V * .3A) + (-5V * .1A) + (+5VSB * 2A) =
185 + 3.6 + .5 + 10 = 199.1 WATTS which is close to the 200W rating.

 

[paparazi]

Forget the maths, forget amperage per pin, simple fact is that they are failing at an abnormally high rate!! so it wouldn't really matter if they were 400watt units, they still need changing.
The manufacturer just doesn't want to face upto his obligations and change the lot!
Minimum 300watts but more important is QUALITY! OK the guy isn't going to supply you will Antecs or Enermax replacements but something better than galvanised steel generic boxes is advisable ie: Qtek or Tsunami 350watters
Martin

Replying helps further our knowledge, without comment leaves us wondering.

 

[jfryer]

I would not feel happy with a 200W for a Pentium 2.4, I agree that 300W is a much safer, trouble free alternative.

But more importantly like paparazi said, it doesn't matter if there are 500W Antec dual fan PSUs, if they are failing frequently then they should be replaced, end of story.

and I would suggest pushing for a 300W replacement, you have ordered a bucket load of machines from this guy so start threatening him with wholesale returns if you are not satisfied.

-------------------------------------------
There is no magic, only onions
-------------------------------------------

 

[SkipCox]

No kiddin'...450 machines with wholesale psu failures is not acceptable by any stretch of the imagination.

You and your company showed good judgement in purchasing 2.4 P4's for workstations and your vendor poor judgement by underpowering them.

IMO you should expect nearly zero downtime with these machines. This is costing your company money and needs to be resolved. Am I correct in assuming this is a quarter million dollar hardware investement you guys can't perform daily work on?

Skip

http://home.comcast.net/~skip9/index.html

http://scc.i8.com

 

[ceh4702]

I would sue them. They pruposely violated the minimum recommended voltage for the power supply based on Intel's specifications for their processor. I would never do business with them again. This is what happens when you listen to a salesman and do not have some technical person who knows what they are doing confirm that it is a solid deal and the computers will hold up. I would take them to court and make them replace every power supply.

If you do not like my post feel free to point out your opinion or my errors.

 

[SkipCox]

I, for one, would like to be kept up to speed on this problem. I don't care about the retailer or manufacturer names, only if this is a cost cutting by them or some other problem.

If you can keep us updated, I'm sure we'd appreciate it.

Best of luck

Skip

http://home.comcast.net/~skip9/index.html

http://scc.i8.com

 

[clickster]

Their opinion is that we received a bad batch of power supplies, bud they don't know how many are bad. Basically, when we told them we were buying 450 PCs but would be receiving them over a period of time, they set aside the parts for 450 PCs. Apparently a bad batch of power supplies must have made it into our order (their opinion). They're now sending us 220W replacement PSs when we RMA one of the 200W ones. Not much of a difference really, unless they're right about it just being a bad batch. When they come up with a new model, they run the new model through 6 weeks of continual stress testing and these didn't have problems. I know this for a fact which is one of the reason that I have a hard time arguing with them as to whether or not they are going out because they are underpowered. The small form factor of the model we purchased (desktop, not mid-tower) means that the power supply has to be extremely small. So they can't send us any of the 300-350W PSs that they use in their towers because they won't fit. We've gotten them to send us 6 power supplies to keep in stock here, so that we can immediately replace them and get them back to their owner and then just replace the stock PS with the RMA PS. That has helped, but is still not ideal. Since they overnight RMAs, I'm not really worried unless we have more than 6 go out in one day. So far 4 is the record for a single day.

 

[TrojanSquirrel]

By my rekoning with your figures I should get a PSU fail at least once a month on my small network...... I don't.

For the most part I'm running on 300W supples and most PC's have high end graphics card, sound cards and four IDE drives. Some also have PSU supplied fans as well.

Perhaps the PSUs are a bad batch, but 300W is a better way to go.