A power supply is an electronic device that supplies electric power to another device, such as a computer, monitor or printer. This is achieved by converting wall power (or mains power) to a lower voltage, and in most cases also from AC to DC. Most power supplies also provide protection from ...

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151
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Should laptops remain plugged in when their battery is 100% charged?

When your laptop's battery is 100% charged, should you leave it plugged in so any battery power doesn't get used, or will that cause overcharging, overheating, etc.? Should the laptop be unplugged ...
32
votes
3answers
3k views

Pulling the plug out for 10 seconds

When calling support the other day he told me to reset my DSL modem by pulling out the power, leave it out for 10 seconds, and then plug it back in. This is something I have heard many times with ...
31
votes
3answers
26k views

How do you check how much power a USB port can deliver?

Some laptops have a special USB port that can deliver more power than the other ones. However it is not always easy to identify which one is the good one, nor how much power it can deliver. So is ...
30
votes
11answers
86k views

Laptop power supplies, does current matter?

I have two laptops (same manufacture), with the same type of power connector. However, the power supplies/transformers are slightly different. The output on the first laptop's power supply is ...
29
votes
6answers
5k views

Can touching any hardware inside a running PC be dangerous for you?

I'm curious, if all the hardware gets power from the PSU's DC power lines, which provide a max. voltage of 12V, can you get electrocuted by touching some of the hardware?
25
votes
2answers
12k views

Why are brownouts so harmful?

I was reading http://superuser.com/questions/32840/is-surge-protection-actually-needed and well I'd like to know why brownouts are so harmful. The explanation gave there is "the capacitors get above ...
22
votes
5answers
4k views

How to test a power supply?

My computer powered off the other day on its own, and now when I push the power button, nothing happens. My assumption would naturally be that the power supply is done (possibly well done) but is ...
21
votes
4answers
1k views

Can unexpected power loss harm a Linux install?

I am developing an application on a Linux embedded board (runs Debian) e.g. Raspberry Pi, Beagle Board/Bone, or olimex. The boards works on an environment that the electricity is cut unexpectedly (it ...
20
votes
6answers
45k views

How to choose a UPS / calculate power for a new PC

Seven years ago a friend gave me a Liebert PowerSure 250 UPS and it has done well for whatever (home) PC and monitor I've plugged into it over the years. I've just ordered a new PC with the Intel core ...
18
votes
5answers
8k views

Why does my PC successfully boot only when unplugged for more than a few minutes?

I have an HP Pavilion Elite desktop computer, model HPE-490t. I like it because it didn’t cost too much, boots itself from an SSD, came with 16 GB of RAM, and has 6 CPU cores for editing video and ...
15
votes
4answers
1k views

Buying A Computer “Case” Fan… Does It Always Run At 100% Unless Told Otherwise?

What happens if I do not plug it into the motherboard and it does not have a switch? I have seen fans before with an "off/low/high" switch that allows you to manually set their speed. I have seen ...
15
votes
2answers
821 views

Identify AC Power Cord with rotated pins

Is this AC power cord connector a standard one? The pins seems to be rotated 90 degrees. This ATX power supply unit (Silverstone ST1500) did not come with the cord and I am hoping to be able to get ...
15
votes
4answers
5k views

Can I run a computer using DC power?

I always thought that using a conventional UPS with a PC is highly inefficient. Power goes from AC -> DC -> AC in UPS and then AC -> DC in PC SMPS. Since PC works only with DC (12, 5 and 3 volts) It ...
14
votes
3answers
7k views

Does a power supply draw only as much power as it needs?

I recently built a small mini-itx Intel ATOM-based Ubuntu home server. The case I choose is a small case but only a full size ATX power supply would fit it. I choose a mid-grade OCZ 500 watt modular ...
13
votes
5answers
25k views

Does laptop charger wastes electric current when not connected to the laptop?

Wonder if when I leave it connected to the outlet but not connected to the laptop, it still consumes electricity.
13
votes
3answers
7k views

Why are there so many pins on a sata power connector?

I was just looking at the power connector for a SATA optical drive, and noticed that it had fifteen pins! I then marveled at the data connector next to it, which has a measly seven pins. I know that ...
13
votes
2answers
1k views

Can using the wrong power supply slow my computer down?

I have a Dell Studios XPS 1640, and it requires a 90W charger for use. I lost my power cable, so I'm now using a 65W charger. My computer has slowed down noticeably whenever it is charging. The ...
13
votes
4answers
10k views

How can I guess if a USB cable will power my devices?

I've had problems with one long (4 meter) USB Mini-B to USB Type-A cable not being able to boot a 2.5'' external hard disc due to not supplying enough current. On top of that, the cable used a Type-A ...
11
votes
4answers
3k views

Can PSU cause my PC to reboot?

I'm having an issue with my PC: It is rebooting sometimes, and I am suspecting the PSU, so I want to confirm a few things. It is a new PC and the first issues started occuring roughly one month after ...
11
votes
5answers
9k views

Ungrounded laptop (Macbook Pro) buzzes in headphones, weird feeling when fingers brush lightly

I've got a nearly 3-year-old MacBook Pro 15" 2.16GHz (MacBookPro2,2). When I am not using the extended, grounded adapter for the power supply, just using the simple, two-prong plug, I can hear a ...
11
votes
2answers
332 views

My 386sx refuses to start in cold days

My old computer refuses to start in cold days. So, in really hot days (about 40ºC / 104ºF ) or even hotter, this PC usually starts, but in cold days, it wont. When the temperature is not in the ...
11
votes
6answers
426 views

are consumer grade power supplies designed to run 24/7?

I know many of you run machines at home 24/7 (servers, maybe even desktops) that run on standard consumer grade hardware/PSUs. Is this safe? Is there even a remote risk of fire hazard? I'm curious ...
10
votes
4answers
2k views

Does my 1000 watt 80gold+ (90% efficient) PSU pull 1111 watts, 1000 watts, or 900 watts from my wall receptacle at 100% load?

Does my 1000 watt 80gold+ (90% efficient) PSU pull 1111 watts, 1000 watts, or 900 watts from my wall receptacle at 100% load? When I plug my 200 watt video card into one of the PCIe power ...
10
votes
3answers
26k views

Laptop touchpad works incorrect when on power supply

My original laptop adapter broke down, so I've bought a new one. It's a no-brand adapter from a dutch internet shop. The power of the new adapter is slightly more than the old adapter, but in my ...
9
votes
9answers
5k views

Will leaving the laptop power brick connected to the power socket be dangerous?

My co-workers (who worked with the company longer than I have) loves to remove their laptop's power cord when they need to move around the office. I frown on this practice since they usually don't ...
9
votes
3answers
1k views

Can I have too high a PSU power rating?

I have just ordered a 650 W PSU for my computer which previously had a 300 W, in order to install a more powerful graphics card. However, I didn't check whether anything would blow up ...
9
votes
4answers
141 views

Is there any computer parts that can be trashed safely (for the environment)?

I have some (non working) computer parts that I want to get rid of. I'm pretty sure most of computer hardware can't be put in the trash safely but I want to know if some of them can. (At the moment ...
8
votes
5answers
520 views

What are these? Are they broken?

Please excuse the poor image quality: What are the components that I've circled in red? The ones on the left look whole and solid. The ones on the right have cracked tops, and although this ...
8
votes
10answers
2k views

Can a UPS be too powerful?

Our old network admin bought the top range UPS a few months ago but never came around to setting it up and is no longer with the company. Now the old UPS broke down and needs to be replaced, but an ...
8
votes
5answers
4k views

Is UPS necessary to have for a PC?

Can my computer components ( Monitor, Motherboard, RAM, HDD, CPU, SMPS) become damaged due to a sudden power flux. It's only needed to shut down Windows properly. Can I solve both Hardware and ...
8
votes
3answers
820 views

Best Way to Protect A Desktop From Power Surge/Dirty Power?

What is the best way to protect a computer desktop from a power surge/dirty power? Would a power strip be adequate? (I don't have much space in my desk.)
8
votes
4answers
758 views

How can I tell how healthy my PSU is?

Simple enough question, I have a hunch that my PSU isn't powerful enough based on a couple of clues: One of my screens flickers, and I read on a couple of websites that this could be caused by the ...
8
votes
2answers
253 views

Computer Shuts Down, BSOD, Aggravation

---BOUNTY & EDIT--- Ok, here is the latest update, and attached a bounty! So I ran all of my ram sticks 1 at a time for around 24 hours each. None of them caused a BSOD. I ran test on all of ...
8
votes
1answer
152 views

Laptop power options while flying [closed]

I have noticed some laptop power supplies include a plug that allows you to connect it to a power source while flying. If I was going to go out and buy a laptop power supply for this purpose, which ...
8
votes
5answers
474 views

How much power is enough?

These days whenever you try to buy/build a PC, you constantly see demands and suggestions for large power supplies. 400W seems to be for low-end machines, Real Men need at least 500W, but if you ...
8
votes
2answers
326 views

Where can I see what caused Windows to make the 'hardware disconnected' sound?

Whenever I switch my desk fan on or off, Windows makes a sound as if a USB device is being (dis)connected. I haven't been able to determine which device is being affected by the power spike, so I ...
7
votes
5answers
13k views

If my power supply is 700w, do I need a 700w UPS?

if my power supply is 700w, do I need a 700w UPS? I am running dual 20" dell LCD's, a i7 quad core system with a radion 4870 1gb video card, 2 hard drives.
7
votes
5answers
1k views

My power supply/motherboard nightmare

Last summer I bought a broken power supply (without knowing of course) and put it in my computer. Turning my box on made one of my cheaper HDDs catch fire (I believe a capacitor or resistor blew) and ...
7
votes
2answers
2k views

Power Supply Capacity Formula

Given that I am building a home computer from scratch and I have several components (MB, CPU, HDD, Video, Sound, etc) which have specific power requirements, is there a formula for me to calculate the ...
7
votes
3answers
165 views

Is there a way to automatically disconnect a notebook from the eletrical power-supply?

I know this looks like weird and useless, but let me explain... I'm running Windows Assessment and Deployment Kit (Windows ADK) to make some tests on Windows 8 Preview. One of it's assessment is the ...
7
votes
1answer
716 views

External “power brick” style PSUs - are they reliable enough?

Keen to build a quiet, power-efficient always-on HTPC/media server, I've been looking at mini ITX boards that have their own external power-brick style power supply. These appeal because they are ...
7
votes
2answers
438 views

New build not powering up at all after connecting psu cables to hard drive

I recently decided to build myself a new, cheap(ish) rig mainly for HTPC use and I have now run into a BIG problem. The system simply refuses to show any signs of life. Problem: When I press the ...
7
votes
1answer
248 views

PC is randomly shutting off

I have a PC which is randomly shutting off (the hard way, like someone pulled the plug). It's no heat problem, because this can happen after 2 minutes of operation or after 4 hours and I checked the ...
7
votes
1answer
15k views

Should I connect two 4-pin EATX12V power plugs?

I have an Asus P8Z68-V Pro motherboard and a Cooler Master Silent Pro 700W PSU. The PSU has two 4-pin connectors and the motherboard has one 8-pin EATX12V connector. It boots fine with only one 4-pin ...
6
votes
10answers
82k views

Why does my computer power off suddenly and without warning?

My computer is about 7 years old. Its has an Asus A7N266-VM motherboard and an AMD Athlon XP 2400+ CPU. My problem is that my computer suddenly and randomly switches off on its own. There is no blue ...
6
votes
6answers
16k views

How can I diagnose a faulty power supply?

I've got an older PC that freezes/blue-screens at non-reproducible times. I suspect that it's caused by a faulty power supply, mainly because I don't have any other idea. How can I diagnose this ...
6
votes
4answers
12k views

Why is the laptop charger thing (transformer) making a noise?

The laptop power cable consists of two cables with a transformer in the middle. The transformer is making a tiny noise while plugged in. I think it's normal... is it normal? What is it exactly?
6
votes
3answers
4k views

Is it safe to use a power supply with a different laptop? [duplicate]

Possible Duplicate: charging laptop with a diffrent manufacture charger I have a Dell Vostro 1500 laptop, but unfortunately I lost the power supply in Indianapolis last month. I have a power ...
6
votes
5answers
5k views

Dell laptop power cable always falls out!

I have a Dell Inspiron 1720 laptop, about 18 months old. The problem is that the power cable keeps on falling out. It's just sitting on a desk, but minor movement can cause it to come out. From a ...
6
votes
4answers
8k views

Does the wattage on a power supply simply mean the max output wattage?

If I have a system running at ~500W of power draw, will there be any tangible difference in the outlet wattage draw between a 1200W power supply vs, say, a a 800W power supply? Does the wattage only ...