Strange PC noise + PSU draw question and Dell MB/PSU question

[Dave Perry]

This is a cross post but I'm a little confused on where this question should go...

I have a 3 year old Dell Dimension 2400 to which I've added a Sony DVD burner and a second HD. I believe the system drive is an 80 gig Maxtor, the 2nd HD is a 250 gig Caviar.

Within the past two months or so I've been noticing that a fairly loud (considerably louder than any other sounds from the computer) sound that I can only describe as like the sound of a metal latch snapping shut---just a brief metallic snap, has come from the computer and it always seems to be once, occasionally twice, during boot-up. It doesn't happen every time I boot up, though, maybe one time in 4. It definitely sounds mechanical to my ears, but I suppose it could be an arc or spark, though it doesn't seem to sound like anything electrical.

Any ideas on what this might be? Is this something a failing HD will do? A fan? I don't think I've ever heard it beyond the minute or so that it takes the machine to fully boot up, and never more than twice in a row during that time. All drives and everything else are ostensibly functioning fine and I've had no apparent problems with the machine other than this weird sound recently.

BTW, it does it with the cover completely off the PC case, so it couldn't be the case cover itself making the noise

Someone on another board reacted strongly that my 200 W Dell PSU is underpowered, but then he started talking about ATX standards and this is a Dell, the only thing's I've changed are changing the CD drive to a DVD drive (only one optical drive and the Dell manual says you can have 2), adding the second hard drive, and a PCI sound card, so it seems like the main extra draw is the 250 gig HD, but as I recall this sound only happens during boot ups, and there a plenty of other times when both HD's are working simultaneuosly. Plus, it could only be a short circuit if it was too much power draw from the two HD's, and wouldn't that cause a BIOS level shutdown? That has never happened.

So, my next question is, with no graphics card (integrated graphics), one optical drive, and two 7200 rpm hard drives, does the 200W stock PSU seem dangerously underpowered? If so, would the computer tell me with errors and/or shut downs if there was about to be a huge failure? I haven't seen anything like this.
.
Also, RE: Dell specific pinouts and adding hard drives, someone said this: "If you do opt to get a new drive be aware that Dell has had in the past a habit of using proprietary PSU's. The pin out being different than that of a standard ATX PSU. This could be the cause of damage to your motherboard if this is the case with this particular model of computer"

This semed strange to me. I knew that you needed a Dell PSU because of the motherboard's weird connector, but why would that affect what HD you could use? The computer came stock with what looks like a standard Maxtor 7200 rpm drive. Is there something "Dell specific" about that? As I stated above, the second drive is a Western Digital Caviar, 7200 rpm, 250 gig. I think he may be getting new motherboard and new hard drive mixed up.

Sorry to throw all this at you but the water just seems to get muddier as I delve into this but I need to know if I'm anywhere near damaging my system and if so, what I can do about it.

Thanks in advance with any help you can give!

Dave

 

[GregANDTCH]

Not all the Dell's have a different pinout on their power supply.
You just have to be careful & check the color coding before you plug a different one into the board.
Regular ATX pinout

Dell ATX 1998 & Later

 

[montag451]

200w is a little low, and Dell psu's are not known for being as sturdy as some of the more popular makes.

 

[FlyingPenguin]

Your metal latch snapping sound could be a hard drive. Click and or clunks from a hard drive are a sign of impending failure.

There's really nothing else in a computer that could make a metalic clacking noise except maybe a bad CD-Rom drive.

Dell over-rates their PSUs. That PSU is probably closer to a 275watt retail PSU. You have adequate wattage for 2 drives, a CD-rom and onboard video. I wouldn't add anything else though.

As long as you're not getting mysterious lockups or restarts your PSU is fine. You could always put a digital multimeter on the 12 and 5 volt rails to check them. They should be within 5% of rated voltage.

I would NOT try to install a standard ATX PSU. Most wont fit prperly without modifying the case. Dell also used to use a non-standard pin out on the mobo power connector up until a couple of years ago as greg pointed out.

Any IDE hard drive will work in a Dell.

 

[mountcarlmore]

dell psus actaully seem to be quality units, i held one recently, and that thing was a rock, about 3 times heavier than the generic psus that were lying around in the shop.

 

[dafuzzbudd]

older cases seem to pop in and out sometimes, probably due to heat disforming the plactic/metal overtime.

 

[Dave Perry]

Originally posted by: FlyingPenguin
Your metal latch snapping sound could be a hard drive. Click and or clunks from a hard drive are a sign of impending failure.

There's really nothing else in a computer that could make a metalic clacking noise except maybe a bad CD-Rom drive.

Dell over-rates their PSUs. That PSU is probably closer to a 275watt retail PSU. You have adequate wattage for 2 drives, a CD-rom and onboard video. I wouldn't add anything else though.

As long as you're not getting mysterious lockups or restarts your PSU is fine. You could always put a digital multimeter on the 12 and 5 volt rails to check them. They should be within 5% of rated voltage.

I would NOT try to install a standard ATX PSU. Most wont fit prperly without modifying the case. Dell also used to use a non-standard pin out on the mobo power connector up until a couple of years ago as greg pointed out.

Any IDE hard drive will work in a Dell.

Thanks for the reply. Would it make sense, if it was a hard drive going bad, for this to only happen during startups, and for it to never happen many times in succession (like the "click of death" is supposed to do)?

I've gotten some feedback on another board from a certified technician who does Dell support calls and he says it sounds to him like there is almost but not quite enough power, and that this explains why everything functions fine except on startup, when the most simultaneuos power demands are exerted to get the drives spinning. He thinks one of the drives is reacting when it can't get quite enough juice at first to get going. He doesn't seem to think this problem, because of it's infrequency, sounds like it is likely the drive going bad, but he says it's possible. Both drives work hard much of the time but only do this while the machine/OS is going through the starting process.

A theory I'm developing is that this only happens when there is a DVD in the drive tray during startup, but I haven't had time to gather evidence for that, but if true it would explain why it doesn't happen during every startup.

I'm just puzzled as to why this problem comes and goes and is limited to the startup period, as well as why it hasn't resulted in any errors or any malfunctions reported by either BIOS or OS.

 

[FlyingPenguin]

Yes. Power up is a stressful time on a hard drive. I have seen hard drives that didn't make the classic click of death, but made a noticeably odd mechanical sound during boot up. Might be the head actuator sticking or something.

However yes, I can see the logic of what the Dell tech is saying. A 2400 was never designed to have 2 drives in it and you may have a drive that's a bit sensitive (or failing) that's reacting to a drop in voltage or current during power up. Your theory that it only happens when there's CD or DVD in the DVD-Rom is also valid. Most CD/DVD Rom drives spin up during boot and that adds to the power demand.

Could be a combination of a weak PSU, a touchy drive, and high current loading.

Have you run the factory diagnostic on the drives to see if they pass or fail?

Another possibility I'll throw at you is that the PSU is failing due to bad capacitors and that it's causing a voltage spike or surge that one of the HDD's is reacting adversely to. The computer is the right age to have a PSU in it with defective caps. A lot of OEM manufacturers got stuck with PSUs (and mobos) with defective caps around 2 - 3 years ago and around now they're all leaking and failing.

I personally had this experience with my own workstation. The HDD would make a funny loud PING noise during bootup (not every time), and eventually it failed. RMA'd that drive 3 times and each drive eventually started making the same noise and would fail immediately after making that noise (not right away but after several boot ups). I was blaming the drive at first but the last RMA sent me a completely different model and it still failed.

Eventually figured out that the PSU had bad caps (when I opened the PSU 3 of the largest caps were bulging and leaking). It worked fine most of the time despite that - rock solid voltages, but on boot up the voltage regualtion when all to hell and the drive would get hit with a power spike that caused the loud ping and eventually damaged it.

If the computer is no longer under warranty you can open the PSU and see if any of the caps are bulging and/or leaking. Some photos here to show you what to look for: http://www.pcstats.com/articleview.cfm?articleID=195

Be aware that although the photos show brown crud oozing out the bottom, it can also ooze out the top, and it will usually look dry and baked because of the temperatures in the PSU.

Don't confuse the white epoxy they smear over the caps to hold them in place for leaking electrolyte. Leaking caps will always have bulged tops and the electrolyte is brown.

Hope this helps...

 

[GregANDTCH]

Hey FlyingPenguin

Dell over-rates their PSUs.

Don't you mean under-rates?
I feel you're trying to say the Dell PSU's have more headroom
than a comparable wattage retail unit.

 

[FlyingPenguin]

Yes, my typo. Dell under-rates their PSUs. That's the case with most OEM systems. Since the hardware is matched to the PSU Dell doesn't have to inflate their wattages.

3rd party PSUs have rather over-inflated wattage ratings (the total wattage is really meaningless - what's more important is the amperate of the all important 5 and 12 volt rails).

Bottom line is that a Dell 300 watt PSU is probably comparable to a Antec or Enermax 350. However, you also need to be aware that Dell and other OEM vendors expect a specific number of devices to be installed. The Dell 2400 for instance has only one HDD cage in it and was not intended to have two drives in it (although since the case is idential to higher end models, you can install an extra drive by installing a 2nd drive cage).