Power supply makes "start up" noise when plugging in

[carrierPigeon]

Edit: forgot to mention that the power supply is H240AS-01 240W, which I then Startpaged and apparently the manufacturer is POINWER.

When I plug in my computer, the computer makes a noise almost like it's starting up. Keep in mind that I have not yet pressed the power button, I've simply plugged the computer in. I think that the noise is coming from the power supply, but that's little more than a guess. After 3-5 seconds the computer is quiet and sounds like a computer that's off should sound.
I recently got this computer basically as "used, for parts," although it very well could have no problems, seller just doesn't know or care to research.
I'm not sure what to make of this. The things that popped into my (amateur) head are
1) the power supply has a defect; or
2) one of the components is drawing power when it should

After starting up normally by pressing the power button, the computer seems to function normally except that I have noticed the DVD drive not being able to boot to DVD (tried 3 different bootable DVDs, two of which I have used successfully with other computers). Also, there was one data DVD that the computer was not able to read. There were a few data DVDs, though, that the computer was able to read.

I guess I should start by disconnecting the power cables one at a time, to see if I can isolate the problem to one component?

I think that I also have the ability to test the power draw of the computer, since I have a UPS. But, I have never used that function, and I'm a bit hesitant to jump into that project right now (installing software on Linux is often not a walk in the park for me since I'm new to Linux).

 

[DrLobotomy]

DVD drive is probably hosed. They make these whirring sounds similar to a power supply fans whirring.

Try that first before the rest of the stuff and maybe save some time.

 

[carrierPigeon]

DVD drive is probably hosed. They make these whirring sounds similar to a power supply fans whirring.

Try that first before the rest of the stuff and maybe save some time.

Disconnected the power from the DVD drive. Symptom remains.
I also unplugged it after that and plugged it back in. It was quiet for the second plug in.

 

[DrLobotomy]

Do you have an extra power supply to test with? I assume you disconnected the data cable to DVD drive ie SATA/IDE/SCSI also.

 

[carrierPigeon]

Do you have an extra power supply to test with? I assume you disconnected the data cable to DVD drive ie SATA/IDE/SCSI also.

The power supply is a weird shape, almost shaped more like my forearm but rectangular. I don't any from any of my other computers are that shape.
I did have the Sata cable still plugged into the DVD drive. I'll try now with it unplugged and edit in a minute.
Edit: disconnecting the SATA cable to DVD drive worked.

 

[GiGaBiTe]

Those long proprietary slender PSUs Dell likes to use are hot garbage. The fan is too slow to adequately cool the unit and the capacitors are junk. I've had to repair dozens of them over the years, usually the capacitors fail and if left long enough, start taking out resistors, diodes and mosfets. Another very irritating failure is the epoxy/glue that is used to keep components from moving around. As this stuff ages and gets cooked by the heat, it starts becoming conductive and can cause the entire unit to fail. I've had to spend hours chipping and scraping it out from under components and all over the board.

If you hear a whine when the PSU is plugged in, I'd suspect something failing on the primary side of the PSU, possibly the line filter caps. They can cause the inductors to "sing" or make clicking noises as they degrade and eventually fail. I would write that unit off, even if it still currently works because it's on borrowed time. If you don't have the skill or know somebody that can repair SMPS power supplies, I'd suggest getting a replacement. Amazon and Ebay have used pulls available for about $20:

https://www.ebay.com/itm/312701202244

 

[plugwash]

I have seen some dell machines, that when mains power is applied, seem to turn on briefly before turning off again. I presume this is a firmware thing.

 

[pendragon1]

I have seen some dell machines, that when mains power is applied, seem to turn on briefly before turning off again. I presume this is a firmware thing.

yup and i have a bunch of HPs at work that do that too. if the machine is running right there is nothing to worry about. its just how the system handles the sudden addition of voltage.

 

[carrierPigeon]

Those long proprietary slender PSUs Dell likes to use are hot garbage. The fan is too slow to adequately cool the unit and the capacitors are junk. I've had to repair dozens of them over the years, usually the capacitors fail and if left long enough, start taking out resistors, diodes and mosfets. ...

... If you don't have the skill or know somebody that can repair SMPS power supplies, I'd suggest getting a replacement. Amazon and Ebay have used pulls available for about $20:

https://www.ebay.com/itm/312701202244

The resistors, diodes and mosfets that you speak of, are those on the motherboard or those are parts in the power supply.

I am not a big fan of buying used ones, unless it's just for a short term fix (like for an owner who will be getting another computer soon).
I more like the idea of moving the motherboard into a new case. Though I have never done that before and I know it's not so easy.

 

[Grebuloner]

The resistors, diodes and mosfets that you speak of, are those on the motherboard or those are parts in the power supply.

I am not a big fan of buying used ones, unless it's just for a short term fix (like for an owner who will be getting another computer soon).
I more like the idea of moving the motherboard into a new case. Though I have never done that before and I know it's not so easy.

Those parts are all on the motherboard, so breaking them is extra bad. There are new PSUs in that model available on Amazon for around $40, but I would not expect any of them to be of any better quality than the original. Buy 2 if you want to keep using this system for a while.

Dell is rather notorious for using ATX connectors with non-ATX wiring, so if you pull the board out and buy a good ATX replacement, there is a risk of total disaster. There are, however, PSU adapters made to make them compatible. What specific model Optiplex are you working with?

 

[BinarySynapse]

Business class PCs seem to be the worst about it. I had three Dell Optiplex 390s last year that would would turn on, spin up the CPU fan full speed, then turn back off when plugged in after the they'd been unplugged for a while. A couple of HP workstations we had in the office for a shadow project did the same thing.

 

[pendragon1]

Business class PCs seem to be the worst about it. I had three Dell Optiplex 390s last year that would would turn on, spin up the CPU fan full speed, then turn back off when plugged in after the they'd been unplugged for a while. A couple of HP workstations we had in the office for a shadow project did the same thing.

ive got opti 760s that do it too.

op, this isnt a problem its just how they act.

 

[GiGaBiTe]

The resistors, diodes and mosfets that you speak of, are those on the motherboard or those are parts in the power supply.

Inside the power supply. When a capacitor fails, it can have several failure modes; The most common is going short or high ESR which puts a heavy current load on components both upstream and downstream of it. This fault condition will burn up resistors, diodes and mosfets in the supply. I've had to replace entire sections of power supplies where this happened, the worst probably being in an Antec Aria 300W unit. A capacitor failed that was supplying a zener diode and caused it to draw so much current that it burned a quarter sized hole in the PCB. I had to repair it dead-bug style with components floating off the PCB since there was nothing left to attach to.

The reason I repaired it rather than replacing is because a replacement was near $100 because it was a proprietary form factor, and even if I did opt for the replacement, I would have still had to recap the newer unit because it had known shitty cap brand in it, IIRC it was United Chemi-Con KZG series caps or Fuhjyyu, both have 100% failure rates.

I am not a big fan of buying used ones, unless it's just for a short term fix (like for an owner who will be getting another computer soon).

Used power supplies can be fine, you just have to be very careful about inspecting them before use. I always remove the lid and do a general visual inspection before powering them on to look for signs of damaged components or stress, which would be a darkened PCB below a component where it got really hot.

I more like the idea of moving the motherboard into a new case. Though I have never done that before and I know it's not so easy.

You didn't specify what model of computer you have, but I'm assuming a Dell since that model of PSU seems to be common in them. It may not be possible to migrate the motherboard to a generic case because most Dell motherboards in the last 15 or so years are either BTX or proprietary and won't fit inside a generic case.

 

[carrierPigeon]

Inside the power supply. When a capacitor fails, it can have several failure modes; The most common is going short or high ESR which puts a heavy current load on components both upstream and downstream of it. This fault condition will burn up resistors, diodes and mosfets in the supply. I've had to replace entire sections of power supplies where this happened, the worst probably being in an Antec Aria 300W unit. A capacitor failed that was supplying a zener diode and caused it to draw so much current that it burned a quarter sized hole in the PCB. I had to repair it dead-bug style with components floating off the PCB since there was nothing left to attach to.

The reason I repaired it rather than replacing is because a replacement was near $100 because it was a proprietary form factor, and even if I did opt for the replacement, I would have still had to recap the newer unit because it had known shitty cap brand in it, IIRC it was United Chemi-Con KZG series caps or Fuhjyyu, both have 100% failure rates.



Used power supplies can be fine, you just have to be very careful about inspecting them before use. I always remove the lid and do a general visual inspection before powering them on to look for signs of damaged components or stress, which would be a darkened PCB below a component where it got really hot.



You didn't specify what model of computer you have, but I'm assuming a Dell since that model of PSU seems to be common in them. It may not be possible to migrate the motherboard to a generic case because most Dell motherboards in the last 15 or so years are either BTX or proprietary and won't fit inside a generic case.

The computer is
Dell Optiplex 7010 SFF Desktop
Intel Core i5-3470 3.2GHz Quad Core

Since the short "bootup" when plugged in isn't an abnormal behavior (as highlighted in this thread), I think I will just leave the computer as is.
Since the computer is kind of low-end due to its age, if something goes (in the coming months) I would be more motivated to move it to a new case and new power supply since those could then be re-used more easily. But, I guess that all hinges on whether that's even possible (the issue pointed out earlier). If not reasonably possible to move it to a new case, I would probably part it out.

 

[GiGaBiTe]

The computer is
Dell Optiplex 7010 SFF Desktop
Intel Core i5-3470 3.2GHz Quad Core

Yeah, it's not possible to migrate this to a normal case. I have an Optiplex 9010 SFF motherboard, which is the same design with a different chipset. The motherboard form factor is proprietary, it won't fit in a standard case because the board is far too wide. It's about an inch and a half wider than a standard ATX motherboard. The mounting holes are also in proprietary locations.

Additionally, all of the board connectors are proprietary, like the fan and front panel connector. The BIOS requires all of these to be plugged in or it will freeze with POST errors. There are Dell 5 pin to 3/4 pin fan header adapters, but the front panel is a smart board that uses a weird proprietary protocol over a 6 pin mini-JST header.

I would be more motivated to move it to a new case and new power supply since those could then be re-used more easily. But, I guess that all hinges on whether that's even possible (the issue pointed out earlier). If not reasonably possible to move it to a new case, I would probably part it out.

The only real choice is to repair or replace the PSU if you want to use the system again.

 

[M76]

I've encountered a DELL psu that makes a noise like, it was like that from new and has been working for 10 years.