Does this look like a dead power supply to you? . . .

[britechguy]

Got a text this morning from one of my recent clients: "We had a power outage and now my computer won't turn on. I have it plugged into a surge protector so I don't know why it didn't protect it. My speakers and my monitor still work. Is there anything I can do to get my computer to turn on? I've tried a different cord. The green light on the back comes on momentarily, but then goes off."

The symptoms strongly suggest that to me, but I am surprised that the green indicator light comes on at all in these circumstances. I thought I'd solicit opinions here before I reply to the client.

 

[ThatPlace928]

Got a text this morning from one of my recent clients: "We had a power outage and now my computer won't turn on. I have it plugged into a surge protector so I don't know why it didn't protect it. My speakers and my monitor still work. Is there anything I can do to get my computer to turn on? I've tried a different cord. The green light on the back comes on momentarily, but then goes off."

The symptoms strongly suggest that to me, but I am surprised that the green indicator light comes on at all in these circumstances. I thought I'd solicit opinions here before I reply to the client.

Sounds like the block on the power supply got zapped. I have one that did the same thing and is now unusable. Before mine died, however, I could hear a sound inside, like something spinning. I think mine was probably bad to begin with.

 

[mmerry]

What brand/model. I have seen Dell Optiplexes that if you reseat the RAM, it starts. I'd do the typical unplug everything from the system and see if I get beep codes.

 

[britechguy]

For the record: Dell XPS 8940 Tower

Thanks for the input and advice.

 

[Larry Sabo]

I assume he removed the power bar from the equation (i.e., didn't just try a different cord into the same power bar). If so, time to swap in a known-good PSU for testing. If no change, probably a motherboard failure. Might first try it on a different house circuit, as well, in case a breaker is failing.

 

[timeshifter]

Dell XPS 8940 Tower

Ugh. I've got one of those in this week that is randomly freezing. A standard ATX power supply does not fit in the case.

 

[Philippe]

The green light on the back comes on momentarily, but then goes off."

Bad PSU. Green light comes on a few seconds (good voltage) then, when the computer needs more watts, it comes off (not enough power / amperage).

 

[britechguy]

A standard ATX power supply does not fit in the case.

Is it an SFX instead? If not what is it? Dell's own site is not helpful nor is the Service Manual in terms of giving exact details. In looking on Amazon quickly, it appears to be some Dell proprietary thing.

 

[Markverhyden]

It almost certainly has multiple rails. So initial power indicates input is good but then some or all of the rails fail to come up.

And you can tell the customer most likely they do not have a _real_ surge protector. More like a power strip with a breaker and then nothing as far as their ISP is concerned. As far as protecting and/or failing, it's a cr@p shoot. Had a strike behind my house, like 20-30' away, a few months ago. Being IT with my lab at home I've got a mess of stuff still plugged i even not running. That look out my cable modem, USG3, the PERC card and port 1 on a 4 port server nic card on my email server. Everything else is fine.

 

[frase]

Have you tested the voltage of the PSU yet? Sometimes the mobo itself can go haywire, so resetting the CMOS can help in some situation.
Look for the CLR_CMOS jumper on the board, take power out and cap the jumper to as per schematics for about 5 seconds. Replace cap to original position then plug in and retry power.

If you do not own a PSU tester you can try the paperclip method to test if PSU powers on and spins or is DOA. This will give you a decent result on power to the PSU. Since it is one of those Dell propetiary brick things, rather than going out of your way to purchase one.

Surge protectors have a life span as well if it is over 5yrs old it would need replacement as well.

 

[britechguy]

I have not done anything yet. I don't even have the machine in my hands yet. This is an online brainstorming session before I get the machine.

BTW, I am not familiar with "the paperclip method" you mention. I do have a tester that can be plugged in to the main PS cable and give information about which rails are functioning.

 

[backwoodsman]

BTW, I am not familiar with "the paperclip method" you mention. I do have a tester that can be plugged in to the main PS cable and give information about which rails are functioning.

On the motherboard connector, short between the green wire and one of the black ground wires next to it. It'll power it on without being plugged into a motherboard so you can test it, or use it to power a hard drive or something.

 

[frase]

I have not done anything yet. I don't even have the machine in my hands yet. This is an online brainstorming session before I get the machine.

BTW, I am not familiar with "the paperclip method" you mention. I do have a tester that can be plugged in to the main PS cable and give information about which rails are functioning.

Well I explained so if/when you do get the system, you can try those methods.
Jumper Method for PSU Test
Soooo not even a slight brain breeze?

 

[dannyict]

Diagnostic button for the power supply known as PSU BIST (Built In Self Test). This tool enables technical support agents to determine if the PSU is working properly.
PSU BIST has 2 diagnostic results – Green LED = PASS, no LED = Troubleshoot (you will need to troubleshoot to fault isolate if the PSU BIST fails).
Proper usage of PSU BIST requires multiple attempts to fault isolate whenever a faulty component is present.
Perform the Power Supply (PSU) Built In Self Test (BIST) to make sure there are no issues with the PSU.

• Do this by pressing and holding the test button on the PSU where the AC cable is connected. The LED will light up if the BIST test passes.
• If the PSU BIST passes, the issue may be with the Motherboard.
• If the PSU BIST fails, please refer to article 594010 on how to troubleshoot using the PSU BIST.

Button above power cord? | DELL Technologies

I have a new Inspiron 5348-23 and cannot figure out what the button above the power cord is for.

www.dell.com

 

[Philippe]

If you do not own a PSU tester you can try the paperclip method to test if PSU powers on and spins or is DOA.

I'm pretty sure it won't test anything. I've seen a lot of PSUs with good voltages & spinning fan, which would fail under load... (the voltage / amperage difference).

 

[frase]

True, I came across this the other month is interesting cool for a project.

Ghetto PSU Load Testing.

 

[johnrobert]

Nearly always PS I would do that fist, if it a dedicated one I hook one up outside the case to test before ordering new

 

[britechguy]

Thanks to all. This client has not called back again, so either she's making due without her tower PC (not likely) or something "healed itself."

If I get a next call the first thing I'm going to suspect if the same symptoms present is a failing or failed power supply.

 

[brandonkick]

I'm pretty sure it won't test anything. I've seen a lot of PSUs with good voltages & spinning fan, which would fail under load... (the voltage / amperage difference).

This is the winning ticket.

I don't trust a green LED on a power supply any more than I do a passing "SMART" test on an HDD.

A load on a PSU (when something is actually drawing heavy current from it) vs voltages on standby are apples to oranges.



My money would be on a crapped out PSU. Lights or no lights.