PC makes clicking noise - now won't start up

Over the past couple days my PC has been occasionally making some weird noises. It is a rapid and intermittent clicking sound. Now this morning it refused to start, I push the power button but nothing happens. It is an old Alienware PC that I bought 5 or 6 years ago. I've replaced the hard drive about a year ago and one of the optical drives as well. I've done a search and most of what I've found seems to point to either a hard drive issue or power supply problems. My own first thought currently is that it is the power supply. Any other people have this sort of thing happen? I'm probably just going to go out and pick up a new power supply this evening after work and try it out and hope that's what it is.

where was the clicking noise coming from?

No idea, it was only making the noise the past couple days. If it had kept happening I would have opened it up and made sure I knew where it was coming from but now it won't even start so I can only make guesses as to what it might be.

A HD failure would still turn the computer on. So my guess is your guess is right; Power supply.

Power supplies can be tested (example at http://www.mcamafia.de/mcapage0/pwrtests.htm) if you are adventurous. There's some more material for different power supplies out there.

Clicking sounds with or without short-circuiting tests are definitely a bad sign.

So, anyway, I went to Best Buy and bought a 400 Watt power supply and just got home. I started to unplug everything off the back of my PC getting ready to open it up, the power cable was last. As I pulled it out I heard a crackle of electricity and decided what the heck I'll keep the power cable plugged in and try to turn it on. It worked! So, I turned it off again (since nothing but the power cable was plugged in) and plugged everything back in. I went to try and turn it on again... nothing happened. Ugh, so confusing/frustrating. What just happened... I don't know. So I started unplugging everything again and as I got to the power cable I thought I'd give it one more shot and turned the power switch on the back of the machine off and on and then pressed the button on the front and it worked. This time, I just started plugging stuff back in quickly as the machine booted up, sound cables, network cables, USB mouse/keyboard, etc... Anyway I appear to be back up and running (for however long this lasts) and I now have a new power supply sitting on my floor waiting for a reason to be useful. I still think I'll have to replace the current old one with the new one, but maybe that can wait until the weekend.

Your current power supply probably has a short in the bundle of wires that come out of it. A lot of stress is placed on these wires and after some time they short out and often become detached from the power supply main board.

It would not be wise to continue to use your current power supply. A short can cause the hard drives to randomly reset resulting in data loss or corruption and/or a short could ruin any number of expansion cards in your system.
Dead shorts or shorts to ground are caught by your power supply.

Ohm's law will show you what's going on:

E=IR, I=E/R, R=E/I
E=voltage
I=amperage
R=resistance

P=EI
P=power in watts
E=voltage
I=amperage

Series resistance=R1+R2+R3+......(amperage is constant in series circuits)
Parallel resistance= (1/R1)+(1/R2)+(1/R3)+......(voltage is constant in parallel circuits)
Series-parallel circuits use both these formulas.

As you can see from the forumula as resistance decreases, amperage increases. All circuits have a protection mechanism that detects when amperage increases too much. Since you bypassed several loads and resistances via the short the amperage spiked and tripped the breaker.

Since a dead short means that any number of circuits and/or components are 'skipped' this results in an increase in amperage. The amperage, if high enough, will trip a breaker in the power supply. This breaker is most likely an automatic breaker which resets after a period of time. This would explain why the system did not work at first and then later started working. Some power supplies have both a manual breaker (for power outages, etc) and an automatic breaker (for surges/shorts, etc.)

It is possible, although highly improbable, that you may have high resistance in one or more of the wires coming out of the power supply. Dirt in the power supply can not only cause shorts but can at time cause high resistance. A high resistance situation is not safe because the power supply breaker will NOT trip. However the wire that has high resistance may heat up to unsafe temperatures. Also the higher resistance will ensure that whatever is plugged into the power connector containing the wire will not receive the correct voltage and amperage. This also will not be caught by the device since the high resistance lowers amperage. This could completely ruin a device if left alone for some time.

Indications of high or increased resistance:

• Mobo fan motors moving slower than normal
• Buzzing sounds from any number of devices
• Sluggish hard drive motors
• Sluggish video card fans
• Increased memory errors or random memory errors that cannot be easily explained
• Unstable CPU operation - CPUs do not like fluctuations
• Clicking sounds from motherboard or power supply- relays and solenoids no matter how big or small will buzz, hum, or seem to click when they lack sufficient voltage to energize. The click is not the solenoid activating but it is the solenoid trying to activate but lacking sufficient energy to do so. It sounds like a spark or an electircal arc hitting metal. Sounds sort of like a small bee buzzing around flapping its wings extremely fast.

You are living on borrowed time with your current power supply. I recommend you replace it ASAP.

Quote:

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Originally Posted by hk_mp5kpdw

Over the past couple days my PC has been occasionally making some weird noises. It is a rapid and intermittent clicking sound. Now this morning it refused to start, I push the power button but nothing happens. It is an old Alienware PC that I bought 5 or 6 years ago. I've replaced the hard drive about a year ago and one of the optical drives as well. I've done a search and most of what I've found seems to point to either a hard drive issue or power supply problems. My own first thought currently is that it is the power supply. Any other people have this sort of thing happen? I'm probably just going to go out and pick up a new power supply this evening after work and try it out and hope that's what it is.

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Sounds like it's the clicking of a power supply safety relay, as other people suggested. Probably one of the wires in the power bundle has a break in it and is making intermittent contact. If it's one of the main power wires to the motherboard, the other wires will attempt to supply the missing current and this trips and retrips some overcurrent protection somewhere in the power supply.

Replace it... soon, before it torches your motherboard.

Yeah, I'll replace it with the one I bought yesterday as soon as I get home from work later tonight. I tried to turn it on again this morning using just the button on the front without success. I had to flip the switch on the back to the off position, press (and hold down) the button on the front, and then flip the back switch back to the on position to get it to come on.

OK, so I swapped out the old power supply for my new one but it looks like the new power supply didn't come with all the extra bits that the old one did so... who needs a 3.5 inch floppy drive anyway nowadays. Yep, I spent about an hour scratching my head and figured out I was gonna have to compromise somehow so I fit everything together as best as I could but I came up one connection short so... goodbye floppy drive, I never used you in more than 5 years but I'll miss you (sniff sniff). At least the computer came up on the first try after the swap out process. Once I'm sure things are stable I'll put all the covers back on the PC.

When I booted up, I noticed it seemed to take a lot longer than usual. I was staring at a blinking cursor prior to the first Windows XP logo screen and I was thinking "Please god let this work." After maybe a minute, it got past that and started loading everything up again as normal.

Why can't they just make a standard connection that comes right out of the back of the power supply? It would make things soooo easy. Just unplug the connection right at the old power supply, take the power supply out, swap in the new one and plug the connection back into it, easy huh? But noooo, they have to make it complicated where you have to unplug every little connector to every device inside the PC just because all these devices are all directly hooked into the cables that come with the power supply. Then you have to make sure you plug everything back in and don't forget something. Bah!

Modular Power Supply Unit, look it up.