Posts tagged pc power supply

PC Power Supply – How to Choose a Power Supply (PSU) For Your PC

587 days

by TwiddleGeek in printer Power Supplies

The power supply is arguably the most important part of a PC. when choosing a suitable unit, several important points must be considered. If ignored, trouble may follow.

1. Dimensions

Before purchasing a power supply for your computer build you should already know the computer’s form factor, ATX, Micro-ATX etc. Make sure that your chosen PSU will fit in your case.
ATX cases require an ATX form factor PSU but some modern ATX supplies at the top end of the power scale are extended in length. In these circumstances a large ATX case may be required. Micro-ATX cases, of course, require a Micro-ATX PSU. however, most Micro-ATX and smaller cases come with their own supplies.

2. Quality

The quality of the PSU is vital. A cheap supply is more likely to fail and when doing so can damage any number of components in your computer. A poor quality PSU is probably the biggest cause of all PC breakdowns. Stick to premium brands. You really do get what you pay for and skimping on this part of a PC is inadvisable.

3. Power

If you are building a simple general purpose PC, then a standard 350-400W power supply will be perfectly adequate providing it is of good quality. This kind of system would be using a mid range CPU and a low-end video card or integrated graphics. If you think you might upgrade your system sometime in the future, then it would be prudent to pick a more powerful supply say in the range of 500W or so.

If you intend to build a high powered gaming PC, then the choice of power supply becomes more complicated. Fortunately the major video card manufacturers now provide lists of PSUs suitable for their more powerful products. It would therefore be wise to consider your choice of PSU and video card(s) together. If you intend to use one or more high-end video cards, expect to be looking at power supplies of 650W upwards. A system containing a powerful overclocked CPU and a pair of overclocked high end video cards plus an array of hard drives and cooling fans will probably require a supply upwards of 750W. A supply this powerful might be longer than a standard ATX supply, so your case will have to be chosen appropriately.

4. Cooling

Modern power supplies are usually cooled by a single 80mm or 120mm fan. The larger fan spins more slowly for the same amount of cooling so if noise is a consideration, the larger fan is best. Fanless and hence silent power supplies are available but expensive. They can also get very hot so good case ventilation is required, however, any additional ventilation fans would make more noise which defeats the object of a fanless PSU. Avoid.

5. Connectivity

Most importantly, make sure the leads on your chosen PSU are plenty enough and long enough for your needs, in particular ensure that the main cable will reach the motherboard’s power connector. Some modern power supplies come in modular form. That is to say the leads can be connected as required, only the main cable is fixed. This can make PC construction both simpler and neater.

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The Computer Repair Technician’s Toolkit – Ten Things Every Computer Technician Should Have

603 days

by TwiddleGeek in internal External Hard Drives

While most computer repair and data recovery technicians understand the need to keep up on the latest technology innovations and computer service techniques, it is equally important to any jobs success to bring the right combination of tools and supplies to every service appointment. Even an experienced PC or server technician can find themselves in a situation where they will need to travel to do a job where they do not necessarily know what they will encounter or which tools they may need once they get there. Following are the ten most important items for a computer field service professional to have with them on any job:

Hand tools. At least one large and one small standard and Phillips-head screwdriver.
ESD wrist strap. This is the single most neglected item by most computer service technicians and also the most important so as to prevent damaging any components through electrostatic discharge.
USB Flash Drive with virus removal tools. Often a technician will find themselves trying to service a single computer that is unable to connect to the internet due to virus or malware infection.
USB Keyboard, Mouse and Network Cables. While this is actually three items I have grouped them together as they are commonly needed for testing and ruling out defective input devices in the computer troubleshooting process.
Laptop or Netbook Computer. In many cases the technicians own portable computer will be the only way to get to the internet to download drivers, view manuals or look up a manufacturers technical support or warranty service telephone number. For network or server technicians this should also include a serial cable with which to connect to and configure routers and switches.
Wireless Router. Home wireless routers fail regularly, so a technician should have one with them at all times with which to replace the customers router if necessary.
PC Power Supply. Few items fail as often or are as easy to replace as the power supply. Having one with you will prevent you from having to return to the site to perform a simple power supply installation.
Flashlight. Since there are many low light areas inside the computer’s case and within closets and basements where cable modems/routers are often set up, having a flashlight will eliminate frustration and make the computer service technicians job easier to perform.
Tie Wraps. While not critical to the repair job itself– keeping cords and cables neatly wrapped up and organized is one thing that distinguishes a computer service professional from an amateur.
Portable Air Compressor. While this item is the least practical to transport it should still be brought with to every computer service job. Many times it will remain in the trunk of the vehicle and not be needed, however should you open the customers computer case and find that it is full of dirt and dust a technician will need to have a way to clean it out.

Few things can be more frustrating or embarrassing to a computer repair or data recovery technician than travelling to a job only to find out that they haven’t got the right tools with them to complete it. By ensuring that you have these ten things with you on every computer service appointment you will eliminate frustration, maintain a professional image and prevent unnecessary repeat visits.

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How can I solve the problem of PC Power Supply Failure?

732 days

by TwiddleGeek in micro Atx Sfx Power Supplies

Power of PC failed without warning. no evidence of any response. all cable connections fine.
Is there any solution in the immediate hardware?
Maybe the Power Supply Unit needs replacing. how do I do that?

PSU is very easy to replace in the average desktop PC. It will be harder to reach all the plugs that are attached to the motherboard and drives than to actually remove the PSU itself.

Expect to pay between £20 – £50. Most people will recommend not to go for the cheapest if you can avoid it. make sure the power rating is at least as high as the one you are taking out (400W – 700W) and, (silly I know to say this) make sure you switch off the mains to the PC before you start work.

PSU is held in place by 4screws.

You unscrew these (make sure it is unplugged please!) and pull out your PSU after disconnecting any cables.

Putting a new one is the reverse.
+++++++++
Response above makes zero sense. A PSU is much cheaper to buy on its own than a PSU installed into a case….

Cheapest way is to buy a new case, and rebuild your PC yourself into that case.

remember how all of the leads are connected, if you just start pulling them out and don't pay attention, it may be a bit confusing.
It is pretty straightforward though.
To remove the unit after disconnecting the leads is simple, most power supplies have four screws at the back of the computer and some have a stabilizer scrw at the exposed side of the unit.
Just slip the new one in and screw it up.
Hook your leads and test it out to make sure your cooling fan is working.
If the cheap little fan gave out on the other one, you should have received an error message stating "fan failure", that is the most common cause of power supply failure, so never ignore that warning.
Power supplies are very cheap, so go on and get one and make sure it is the right wattage for your computer, ie., 250 watts, 400 watts, etc. it will be marked clearly on the old one.

One probability is SMPS = Switch Mode Power Supply, if this malfunations the power would not go to the PC. try getting a new one.

If u know any hardware person ask him to try an old working SMPS, it it works on that then buy a new one.

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Car Amp Project

753 days

by TwiddleGeek in power Supplies

Using A PC Power Supply to Power A Car Amp And A 15in Sub

Recently a friend of mine wanted to use some car components in his home stereo. the idea was to go from his home stereo subwoofer pre-amp out into the car amp, then to the 15 in sub. the problem was getting a power supply that could supply the power necessary for the amp (even when the amp was putting out a good amount of bass). after some researching I decided that the easiest option would be a computer power supply.

We had an extra 500w power supply laying around. this power supply is capable 25A on its +15v line. the power supply is a little on the low end side to power a car amp. In the car the amp would get ~14v and towards ~50A or more can be provided by the alternator. Because of this we decided we would at least need to get a capacitor to smooth out the voltage a little and help protect the power supply.

We started testing without the capacitor. to turn on the supply we connected pin 14(green) and 15(black) on the ATX connector

On our first test we just used in extra female Molex connector to connect the amp to the computer power supply. this was proof of concept. the Amp was working and it actually sounded good, but we didn’t want to put too much of a load on the power supply. For the amp to turn on it needs a + voltage to the Remote line. We connected the remote line to +12v.

After our initial test we got rid of the unnecessary wires on the power supply. We need to keep the green wire (PS_ON), a yellow wire (+12), and a black wire (GND).

For the power supply to turn on the green and the black wire have to be connected. For now they are just manually connected. we will change this when we get the rest of our parts

A few days later we got our capacitor. it is a 3.0F capacitor. We soon found out that until the capacitor is charged, it acts like a short. We had to get a resistor so that the power supply wouldn’t shut off when hooked to the capacitor. RadioShack only had 100ohm 10w power resistors. We hooked 8 of them in parallel (to give us 12.5ohms). this allows the capacitor to charge without shutting off the power supply. it is still a little slow charging. I believe that is because when the capacitor is at a short, a 12.5ohm resistor only creates 0.96Amps. We ordered 3 1.5ohm 100W resistors for 0.5ohm in parallel, creating 24A , unfortunately the vendor could only supply one of them, meaning we will only have a current of 8A

Because the resitor is dropping power, it was not a high enough voltage for the capacitor. the capacitor would start alarming under 10v. Ifound that if we took of the load(thye amp) and let the capacitor charge to 10v volts, we could bypass the resistor(notice the red wire in the pic below) and the power supply wouldn’t turn off. this allows us the maximum that the power supply can put out without having the voltage drop from the resitor.

Once the capacitor was charged we can turn the amp on. the sound was really good, and this was just our test Amp.

View the test video here –> Test PC PSU CAR AMP

More Pictures –> Pictures

Currently this is set up with an audiobahn amp

We are not done yet, we are still waiting for a few parts.

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