Dell power supplies

[kelly]

There has been some discussion here about Dell not using standard power supplies. I'm getting a Dell in here tomorrow that doesn't start. Problem happened after a thunderstorm.

So I'm wondering if the power supplies in new Dells (this one is a year old) are of the standard type. I want to substitute a 'normal' power supply with the one presently in th machine to see if it's the PS.

thanks
-td

[golfmore]

I tried to help a friend with a Dell. One a few years old, and it's supply was gone, also proprietary. The cost reflects that as well. A 300 watt supply for it was $89 + shipping. Good grief!!

[kelly]

I replaced a PS in a Dell Dim 4550 back in Feb. It was a 250W unit. Cost was about $40 with shipping.
- tony

[kelly]

Since I haven't received a response on how to tell if this Dell PS is proprietary or not, I'm going to assume it is not. I'm saying this because it's only a year old and I know that a Dell I worked on a few months back did not have a proprietary PS.

I'm going to test it by pulling pin 14 down to pin 15 via a 100 ohm resistor. I think that should simulate what the mobo does to turn on the supply. I'll then check output voltages. The test will be done without a load. Has anyone done this?

- tony

[PeteF]

Since I haven't received a response on how to tell if this Dell PS is proprietary or not, I'm going to assume it is not. I'm saying this because it's only a year old and I know that a Dell I worked on a few months back did not have a proprietary PS.

I'm going to test it by pulling pin 14 down to pin 15 via a 100 ohm resistor. I think that should simulate what the mobo does to turn on the supply. I'll then check output voltages. The test will be done without a load. Has anyone done this?

- tony

You should not test switching power supplies with no load.
Best to use a simple PSU tester.

Whatever PSU you use to test with, make sure it is designed
to have "short circuit" protection. This way if the Mobo or any
component is damaged with a short or heavy load, you won't
damage your test PSU.

Cheap under $20
http://www.xoxide.com/coolmax-24-pin-power-supply-tester.html

As for proprietary, I believe that's becasue of the physical dimensions
of the PSU and not the output voltages. Again the PSU tester can be
your guide for that. I'm not an expert PC builder so maybe someone
else can assist here on the voltages issue.

What I have seen is that all PSU's I've tested, some do not provide
the -15 Volt output. Some PSUs have an additional connector (3 wire,
I think) that connects to a fan control on the mobo but I seem to
recall that it's not escential to use that connection if the
replacement PSU does not have the extra connector.

I have found that those cheap PSU testers only give you a general
idea if the PSU is good or not. I mean to say, it will tell you for sure
if the PSU is dead but it won't nesesarilly tell you if the voltages
remain constant under normal load. Nothing is better than checking
the equipment using a replacement PSU.

Again, I'm not a PC Builder, I deal mosly with software solutions
but most PCs I've checked that were dead due to lightning damage,
both the PSU and the Mobo were damaged.

---pete---

[kelly]

Pete,

Thanks - that looks like a nice tester. I assume that it actally loads the power supply as it says it does get hot. So I'm going to order one. Thank you.

On the Dell - I found no standby voltage on any of the pins so I have to assume that it is bad. I just hope that it didn't take anything else out. The last Dell I had here with the exact symptoms - only the power supply needed to be replaced.

thank - tony

[photolady]

Tony newer Dells (in the last two years) do not have priority psu's. You can use any one of your choice to replace the bad one. Antec, Enermax, Enlight, Fortron (FSP), Sparkle or Thermaltake are the best and would last longer than off brands would, giving user a better than average chance to having a psu that produces the power it's supposed to produce.

[kelly]

Photolady - thanks. That's what I expected. I went ahead and ordered a Dell replacement for the customer anyway. It's now installed the she has the machine back.

The only problem with replacing the original is the placement of the power cable. I haven't found a power supply that fits into the opening in these Dells. You have to notch out the opening to allow for power connection/power switch on generic power supplies. I have to admit that I didn't look to hard either. I was just checking out the ones in stock at Micro Center in Radnor.
- Tony

[Smokey]

As Photolady said, for Dell desktops now, most of them haven't used proprietary ps's in years. Now for servers and specialty form factor machines is a different story, but for the desktops, they are normal ps's.

[photolady]

The problem I find with Dell's power supply's is they are lower quality and output. Plus the expense. I try to steer away from having to order Dell parts like psu's, just so I can give my customers the quality and power they need to run all the extras they had me install. ;)

[golfmore]

They typically are proprietary. Found that out on the last one I replaced.

[kelly]

How do you handle the fact that some of these supplies don't conform to the same cutout on the computer case? I couldn't find any at the local Micro Center computer store where I didn't need to notch out the cutout on the case to fit the supply in.

- tony

[kelly]

golfmore - the last two (and only two) Dell machines I had in here for PS replacement used non-proprietary supplies. They powered up find on generic supplies. However, like I said earlier, the cutout in the case didn't match. You'd have to notch out the opeing to phyically fit the supply, otherwise I didn't see proprietary - electrially or physically.
- tony

[mylanta]

Most of the time when your psu does not seem to conform to the case, it will upside down...

[photolady]

Ditto what Rich said. But I also had a priority Dell Dimension 8300, here last week. Even turning the non Dell psu upside down would not have worked, as the original had no on/off switch. Though the psu was not priority in itself, the case was.