Question about Antec SP-400 400-Watt Power Supply

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Fan in power supply not working, computer powers up but no video display. Tried a different graphics card same result. It is possible that the power supply is not providing power to the adapter card

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If the fan in the power supply is not running it might be due to old age and dirt and lint keeping it from turning. In almost every case I just replace the fan in the power supply and every thing is ok. If the power supply doesn't keep cool it will shut down on thermal overload.

Posted on Dec 25, 2014


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Posted on Jan 02, 2017

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SOURCE: Nothing on my computer was working. Screen and

This has to be plugged into a motherboard and the switch to it as well is controleed by motherboard so no it will not come on just by applying power. I would try another supply for you inital issue if that does not turn on then what you got here is a cable backwords or a motherboard malfuction of some type.

thanks if this helps please rate it.

Btw, I’m available to help over the phone in case u need at

Posted on Dec 19, 2009

  • 217 Answers

SOURCE: I have an Antec Truepower

Test it. Unplug the molex connector from the mothrboard. You can use a wire or a paper clip to test it to power on. You will connect (short) pin 14 to and ground pin. (diagram here) For example, put one end of the paper clip into pin 14, and the other end into 13, 15, or 16. If the power supply turns on and fan running then maybe a problem with the front panel switch on the computer case.
P.S. make sure you unplug all other leads to drives before doing this.

Posted on Apr 06, 2011

  • 27725 Answers

SOURCE: computer wont boot up. no fan, nothing. tried to

Test your PSU or replace it if your power supply units fan is not working your PSU is faulty

One bad lead can cause a computer to continue on a cycle or to shutdown or fail to detect/ boot up a computer hard drive

Test all leads that attach to your hard drive including electrical extensions,IDE,SATA

the leads from your "((MOTHERBOARD TO YOUR HARD DRIVE))" make sure they have a secure connection and are not faulty or just replace them they could be faulty
make sure all leads that are attached to your drives dvd\cd 3 1/2 inch floppy have secure connections and are not faulty even the electrical extensions or just replace them they could be faulty a computer needs its connections to continue its cycle and have an end so any faulty leads will end up with a computer error even something as small as a faulty electrical extension or fan lead can cause this problem

computers need all of the data and electrical current to travel through every working device and to have an end to be able work properly

a motherboard and a hard drive any leads between them will fail before your motherboard or your hard drive if its a flat ribbon 40 pin type IDE replace it this will be the first to fail check all electrical power input and extensions make sure they are securely seated even the cd/dvd floppy drives need to have current go through make sure these drives are working

also check the Cmos battery has charge and computer RAM modules make sure they are securely seated with no dust built up or in the sockets

the PSU has 4 screws at the back of a desktop computer once you have taken them out and diconnected the power it should slide out just make sure the new onw has the same connections as the one you already have you could get a heavy duty one if you have added a bigger hard drive another cd/dvd more RAM or anything else that might drag more power out of the PSU

hope this helps you

Posted on Aug 24, 2011

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Nothing showing on display when powered on. i have tried everything i can, and i get no beep code. and is there any way to tell if the graphics card is dead?

First thing I would do is make sure it is powered on, make sure the VGA (or dvi) cord is firmly plugged in at each end. If so, and if you do not see anything at all when booting up, I would borrow a monitor from a friend or another computer. If it too does not work, then possibly the video card is faulty. It could, however, also be a bad power supply. Sometimes only part of the power supply goes bad, so some of the lights will come on but it does not boot up, or maybe not provide the power for the video card to work. If this is an add-on card, and if there is a VGA plug on the back of your computer, I would remove the video card and plug the monitor into the original VGA plug.

Dec 22, 2017 | Graphics Computers & Internet

1 Answer

On board video card is not working on A7V8X-LA motherboard

No Signal means no video signal from the computer.

Means the computer isn't sending a video signal to the monitor.

Logic would dictate that the problem is the graphics chipset.
Whether it be Integrated Graphics (OnBoard) of the motherboard, or a separate graphics card.

However there is a different culprit, and one that is often overlooked,

Power Supply

A Power Supply with a weak voltage power rail, will not have enough power to turn the Processor (CPU) on.

1) If ALL of the LED lights were on at once, they would use less than 1 Watt of power.

2) EACH fan uses 2 to 3 Watts of power

3) A typical Processor can use 51 to 125 Watts of power,
Just depends on what Processor it is.

This is why one may see LED's light, and possibly fans spin, but No Signal.
Not enough power to turn the Processor on.

Computer dirty inside? That just 'kills' a Power Supply.

The cooling components for a Power Supply, is the Heatsinks used inside, and a small internal fan,

Click on the photo of the exposed Power Supply, to enlarge.

Looking in-between the letters B and C, plus C and D, you see Heatsinks.

Fins arranged in block shapes, and attached to a single piece of long metal.
The Heatsinks absorb heat from whatever object they are placed against.

The thin fins of the Heatsink then radiate the heat away.
Air flow from the small internal fan, helps carry heat away from the fins of the Heatsink's.

When dirt, dust, hair, carpet deodorizer, lint, name it; coats the fins of the Heatsinks, and the blades of the fan, the Power Supply overheats.

Heat = Wasted Energy

The Power Supply tries to keep up with the call for power, but eventually components inside fail, (Go bad), and the Power Supply fails.

Number one thing when diagnosing a desktop computer, is to make sure the Power Supply is good. Make sure it is putting out the correct voltages.

Power Supply is deemed to be good, THEN go on.

Next thing in the list for desktop computer failure, is the computer is dirty inside.

The Power Supply in your personal computer (PC), is an Converter.
It converts the high AC electricity from your home, or business;
(120 to 240 Volts AC, depending on country), into 3 low DC Voltages,

A) 3.3 Volts
B) 5 Volts
C) 12 Volts (ALL are DC Voltage)

In comparison two D cell flashlight batteries produce 3 Volts DC.

ALL Orange wires are 3.3 Volts
ALL Red wires are 5 Volts
ALL Yellow wires are 12 Volts

ALL Black wires are Ground wires.

A multimeter set to DC Voltage, is used to check those power rails.

Use a KNOWN to be good, Compatible power supply, for a temporary test unit.

Power is known to be good now?
Then I concur the Integrated Graphics on the motherboard may be bad.

Use a graphics card.
Using a graphics card bypasses the motherboard Integrated Graphics. Attach the monitor to the graphics card.

FOLLOW Anti-Static Procedures.

Graphics card is installed. Monitor hooked up to it. Turn the computer on.
You should get a display, albeit it is going to be a 'Fred Flintstones' looking screen.

Screen resolution won't be correct, and Color quality will probably be 8-bit.

Looks worse than a computer using Windows 95.

That's OK. You can now install the Drivers for the graphics card, because you can now at least SEE the screen.

Post back in a Comment.
Want to know about Power Supply first.


Mar 15, 2013 | HP Pavilion Computers & Internet

1 Answer

I have done all that you saud to do. Now the problem I have is the computer will not turn on at all. It's like the power has been turned off from inside the operating progam. I have windows 7, is this...


Phase 1
After power button pressed, computer will detect 5 components :
1. Power supply - OK (enough power)
2. Main-board - OK
3. Processor - OK
4. Memory - OK
5. Video Card / VGA - OK
== beep sound .. (1 time) or on the monitor, display appears BIOS ==

The characteristics of damage to power supply
1. Power supply fan does not spin

Video power supply fan not spinning

If the power supply fan is not spinning, the possible cause of damage to power supply. Solution, replace the power supply.

How to check the damage to power supply
2. Power supply is weak (resulting voltage power supply can not turn on the computer or the voltage is less)
The characteristics of damage to the processor

Normal fan without processor

Normal fan with processor

Based on experience, the possibility of damage processors is very small. To check for damage to the processor, install the processor to another computer (for comparison).

The characteristics of main-board damage
Because the new main-board, so the possibility of the main-board damage, very small. The characteristics of damage to the main-board, when the power button is pressed
1. Power supply fan not spinning
2. Processor fan is not spinning
3. Casing lamp is not lit
4. Main-board lamp does not light

The characteristics of the memory damage or dirty memory
1. The characteristics of normal memory, but installation is not correct or dirty

When the computer is turned on, the sound



Picture a
Release Memory

Picture b
Clean the memory slots with a brush

Picture c
Clean the gold layer memory with a pencil eraser

Picture d
Reinstall the memory correctly

The characteristics of damage to video cards

Solution, remove the video card, clean the gold layer with a pencil eraser.

I hope this information helps.

Oct 23, 2011 | Computers & Internet

1 Answer

When i on my desktop it show blue screen and says no signal analog

That means that the monitor is not getting a signal from the computer. There are several possible issues involved. 1) Make sure that the computer tower is on. 2) Check that the video cable is connected to the active port on the desktop. (Computers often have video connections on the motherboard and an added video card. The motherboard connection is disabled when the video card is active. Similarly if there are several ports (VGA, DVI, HDMI, Display port) only one may be active.) 3) Try a new video cable (if possible) and one of the other video ports (again if possible). 4) Try connecting a different monitor to the computer or connecting this monitor to another computer.

Open up the computer and check if the card requires a separate power connection to the power supply. Make sure it is plugged in. Do the fans in the computer spin up?

If a second monitor doesn't work or the monitor works on another computer, then the problem is with the video adapter on the computer, the power supply or the power switch. Please add a comment with more information about the type of desktop and the current video graphics adapter (on the motherboard or separate card). I will provide additional help if possible.

Cindy Wells
(who has a computer in the company that needed a new monitor (power supply failed) a few months ago and lost the fan on the video card last week. Without the fan, the card overheated and shut down. Thus no signal to the monitor.)

Oct 02, 2011 | Computers & Internet

1 Answer

I have a problem with a X1550 video card, 512 Mb, it seems to have bad contacts on the pci express slot. When i turn on the computer it displays only vertical lines, after repositioning the video card in...

looks like that your vid.card has a compatibility issue.
but since that you've tested this w/other computers and still the same?but your computer works on other
that means,there's a big chance that your vid.card is already busted.

Sep 09, 2011 | Power Color POWERCOLOR ATI RADEON VC X1550...

3 Answers

Starting from about 2 days ago, my monitor has been unable to receive input signal from the computer (Pavilion Elite m9515y). I had originally thought that there was a virus at work, so I scanned for...

"I'm thinking faulty video card2_bing.gif, though I'm not entirely sure."

I'm thinking Power Supply.

Bad Power Supply, weak Voltage power rail.

No Signal on the monitor indicates the monitor is working, but the monitor is not receiving a video signal.

1) Could be due to a faulty monitor cable.
When you used the other monitor, did you try another monitor cable, or is this a VGA monitor where the monitor cable is not removable? (CRT monitor)

2) Monitor cable checks out, the next part of the diagnosis would be the graphics card.
Nvidia GeForce 9600GS


It's a Nvidia GeForce 9600 GS 768MB DDR2
One of the weakest graphics cards, (graphics wise), in the GeForce 9600GS series,

As stated, ensure that the graphics card is seated, down in the PCI Express x16 expansion slot.

[Computer unplugged from power. Observe Anti-Static precautions Before you reach inside the computer.

Anti-Static precautions:

Your body carries Static electricity.
Static WILL fry out (Short Circuit) the hardware components inside a computer.

Computer unplugged from power, computer on a table, computer case open,...TOUCH the metal frame of the open computer case to relieve your body of Static.

Should you walk away in the middle of working on your computer, upon your return Touch the metal frame again ]

After ensuring that the graphics card is well seated, and this is to no avail, I would check to see if the Processor fan is operating.

Computer on, computer case open, observe the Processor fan.
If it isn't spinning, or seems to be spinning very slow, replace the fan.
(Bad fan bearings)

The Pavilion m9515y uses an AMD Phenom X4 9850 processor.
An AMD processor will heat up very quick.
(And typically runs hotter than a comparable Intel)

Without a fan running the Processor could burn up in a matter of seconds.

There is a Fail Safe feature built-in, to shut the Processor off if it becomes too hot.
(BIOS turns it off)

Processor fan is operating okay?
Use the Integrated Graphics on the motherboard, and see if the graphics card is the problem.

The Pavilion Elite m9515y desktop computer has a PCI Express x16 slot, (PCI-Ex16), and also has Integrated Graphics.

(ATI Radeon HD3200, GPU, for Integrated Graphics)

To explain:
The GPU is the 'Graphics Engine'
Graphics Processing Unit.

The GPU chip can be soldered directly to the motherboard, (Integrated Graphics), or soldered to a removable graphics adapter card.

(Integrated Graphics is also know as OnBoard Graphics.
On the motherBoard)

When a graphics (adapter) card is used in the PCI Express x16 slot, the Integrated Graphics is not used.

You can remove the graphics card, plug your monitor into the Integrated Graphics on the motherboard, and reset BIOS to use Integrated Graphics, instead of the graphics card.

Graphics on your monitor?
You know you have a bad graphics card.

[Computer unplugged from power, anti-static precautions observed. Remove the graphics card. Plug the monitor into the Integrated Graphics of the motherboard.

{The Integrated Graphics ports are above where the keyboard, and mouse plug in. (Using a keyboard, and mouse that has a PS/2 connector, not a USB connector)

There is a DVI port, (White. Has three rows of 8 holes, and a horizontal slot to the right of the holes),
and a VGA port, (Blue. Three rows of 5 holes)

Plug your monitor cable into the appropriate Integrated Graphics port.

Press the Power On button in, and hold it in for a count of Five seconds. (And I mean at least Five. Count 1001, 1002, 1003, 1004, 1005)

Let go of the Power On button.
Do this procedure two more times.
What you are doing is clearing CMOS Error Codes, and resetting BIOS back to the factory default settings.

Plug the computer into power. WAIT 1 minute.
Turn the computer on ]

After checking out the monitor cable, and Processor fan, I would like you to bypass the graphics card part of the diagnosis, and check the Power Supply instead.


1) The major cause of computer failure, is Power Supply failure.
Largely attributed to the inside of the computer is dirty, as well as the inside of the Power Supply is dirty.

(The second cause of Power Supply failure, is a low quality Power Supply.
Gauge of wiring is too small.
Electrolytic Capacitors are low quality.
Rectifier Bridge is low quality.
MOSFET's are low quality)

The Power Supply has two cooling components.
The Fan, and Heatsink's used inside.

Typical construction of a Heatsink is a plate of metal, with tall, thin fins protruding from it.

The plate of metal absorbs heat from whatever object it is placed against, and the tall, thin fins absorb the heat from the metal plate.
The fins radiate the heat away.

If a fan is used in conjunction with a Heatsink, (Such as a Power Supply for example), the air flow from the fan, helps to carry away the heat from the fins.

Once 'Gunk' builds up on the Fan, and the Heatsink/s, the cooling capacity of these two components drops tremendously.

Heat = Wasted Energy
The more heat, the more the Power Supply strains to keep up with the call for power.
Eventually hardware components inside the Power Supply fail, and the Power Supply itself fails.

1) ALL the lights use less than 1 Watt of power.

2) EACH fan uses 2 to 3 Watts.

3) A typical Processor can use from 51 to 125 Watts.
Depends on what Processor it is.

(Pavilion m9515y uses an AMD Phenom X4 - 9850
Operating at full capacity this Processor can use up to 95, or 125 Watts. Depends on which Part Number it is.
HD9850WCJ4BGH or HD9850XAJ4BGH )

This is why if you are seeing lights light up, and fans spinning, (or spin a few times, and stop), the computer itself may not be working.

Not enough power to turn the Processor on.

A computer Power Supply puts out three main voltages.
A) 3.3 Volts (Wires with Orange insulation)
B) 5 Volts (Red wires)
C) 12 Volts (Yellow wires)

Test is done to specifically check the 12 Volt power rail.
11 to 13 Volts is okay.
Less than 11 Volts requires replacing the Power Supply.

The test is done with a multimeter, or a power supply tester.
(An economical multimeter good enough for this test, will run from $5 to $12.
Here is one example of an economical power supply tester,

Need clarification of something I've stated, or have additional questions, please post in a Comment.
(Believe upper right of your page. We are undergoing changes to improve our website)

By the way.

You have one heck of a computer there.

AMD Phenom X4-9850, and 8GB's of DDR2 Sdram ram memory, (PC6400)
With a decent, not too expensive, graphics card, and a decent Power Supply, you could S-M-O-K-E a lot of gamer computers out there.

Jun 15, 2010 | HP Pavilion Elite m9515y PC Desktop

2 Answers


When a monitor displays No Signal, it is an indication that there is no video signal going to the monitor.

The monitor is working fine.

1) Could be due to a bad monitor cable. They do go bad.

Test would be to take that monitor cable, (If it disconnects), and use it on a known to be working computer.

2) Could be the graphics of the computer.

If the computer has Integrated Graphics, the test would be to install a graphics card, and plug the monitor into it.

[Integrated Graphics is also termed as OnBoard Graphics.
On the motherBoard.

The GPU is the graphics 'engine' of a computer.
Graphics Processing Unit.

It can be soldered directly to the motherboard, (Integrated Graphics), or soldered to a removable graphics card. ]

When you install a graphics card, (graphics expansion card), the Integrated Graphics is bypassed.
The monitor plugs into the graphics card, not the motherboard.

Could be wrong, but I'll bet it's the Power Supply.

If this problem directly relates to a Compaq Presario SR1550NX, the computer is 5 years old. (According to my sources)

If the computer isn't cleaned inside, and the Power Supply isn't cleaned inside, on a regular basis as needed, the Power Supply is one hardware component that is sure to fail.

It's the top problem relating to computer failure.

The cooling components for a power supply is it's fan, and Heatsink's that are used inside.



The basic physical makeup of a Heatsink is a flat plate of metal, with tall, thin fins protruding from it.

The flat plate absorbs heat from whatever it is placed against, and the tall, thin fins absorb the heat from the plate.
The fins then radiate the heat away.

If there is a fan used along with a Heatsink, (Such as in the Power Supply, or on a Processor), the fan moves air in-between the fins, and around the fins, helping to carry the heat away.

If dirt, dust, hair, etc. is clogged on the fan blades, center hub, and surrounding cage, the cooling capacity drops tremendously.

The fan cannot move the needed amount of air.

To include on the Heatsink/s inside the Power Supply.

The gunk acts like an insulating blanket, causing the Heatsink to retain the heat, not conduct it away.

Heat = Wasted Energy

The Power Supply tries to keep up with the call for power, and eventually cannot, due to hardware components failing inside.

The Power Supply may seem like it is operating okay.

Lights light, fans spin, and it may sound as though the Harddrive inside is operating.

The Power Supply could have a weak Voltage power rail.

Power Supply's are rated in Wattage.
1) ALL the lights use less than 1 Watt of power.
2) EACH fan uses 2 to 3 Watts.
3) A typical Processor can use anywhere from 51 to 125 Watts.

A bad Power Supply with a weak Voltage power rail, will have enough power to light lights, and maybe spin fans, but not enough power to turn the Processor on.

Harddrive sounds like it is working, because the Platters inside are being spun by the Spindle motor.

There is no Processor operating (The 'Brain') to find the boot sector on the Harddrive.
Platters are spinning but the Arms aren't moving the Read/Write heads across the Platters.

In short the computer is not operating.

No video signal to the monitor, because there is no computer operating to send a video signal.
Bad Power Supply.

Jun 06, 2010 | HP Compaq Presario SR1550NX (PY059AA) PC...

1 Answer

Asus p4p800s-x won't boot and no display on the monitor..

get a better power supply, as i understand it, youre computer is getting too little power from it. pick a power supply with more volt

May 28, 2009 | Intel ASUS P4P800S-X 848P Socket 478 DDR...

1 Answer

Graphics card won't work on computer

I cant be sure since I can't see the error during bootup. But its highly possible that you forgot to plug in a extra power cord that goes into the video card. at the upper corner of the video card. you will see a black plug with 4 pins on it that needs a power source. You have that from your power supply that normally people use it for a floppy drive. Plug that in here and that should work. If it still doesn't, give me the exact error during bootup and I'll help you from there.

May 11, 2009 | MSI NX7800GTX-VT2D256E GeForce 7800GTX,...

1 Answer

"No Signal" on monitor after boot

hi try to use different slot on your motherboard see if that helps if not try different video card...if that didn't help it might be your motherboard that went bad

Aug 23, 2008 | HP Pavilion a400n (DQ173A#ABA) PC Desktop

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