Should I use the 24-pin or 20-pin for my PC's motherboard

[kwfine]

Hi Raymond and all,

Recently my PC restarted itself automatically and randomly.
I thought the problem might be cause by the PSU, so I replaced it with a new one.
But I have encountered another new problem.
When I opened the PC's case, I saw that the motherboard got a 24-pin socket but the socket was connected to a 20-pin connector from an old PSU.

I wonder if it will do any harm to the PC if a 24-pin socket on the motherboard is connected to a 20-pin PSU.

Further to my PC's problem,
I have replaced the old PSU with a new one.
I also have done some memory test by memTest86+.
But the problem still persists.
Do you have any ideas what else caused this problem?
I noticed that if I pressed the Power button hard to turn on my PC,
then the PC would run steadily, still I am not sure if it is related to the problem.

Please help if you could.

Kitty

[hellnoire]

Recently my PC restarted itself automatically and randomly.
I thought the problem might be cause by the PSU, so I replaced it with a new one.
But I have encountered another new problem.
When I opened the PC's case, I saw that the motherboard got a 24-pin socket but the socket was connected to a 20-pin connector from an old PSU.

I wonder if it will do any harm to the PC if a 24-pin socket on the motherboard is connected to a 20-pin PSU.

It shouldn't, unless it backfired and fried your board, but if it did, then you'd be smelling burning parts...

Further to my PC's problem,
I have replaced the old PSU with a new one.
I also have done some memory test by memTest86+.
But the problem still persists.
Do you have any ideas what else caused this problem?
I noticed that if I pressed the Power button hard to turn on my PC,
then the PC would run steadily, still I am not sure if it is related to the problem.

Please help if you could.

Kitty

Is the PSU the same voltage as the other one? Or what are their voltages... it sounds to me like you've got a weaker one then your computer needs.

I've got a 350w power supply myself, and since my computer isn't 'tricked out' as they say, it does enough to get by, that's all it needs. But the more stuff you add to your computer, the more power gets used.

You haven't explained anything else about your hardware, which leads me to believe you've got a power supply that's too weak to handle your computer. Post a list of the components that are attached to your computer, and how powerful your PSU is, we'll figure something out.

[kwfine]

Thanks hellnoire for your reply and help.

The old PSU got 500W, and the new PSU was a 550W one.
They both support 20-pin and 24-pin sockets.
Here is the list of the hardware on the motherboard:
One 500GB SATA HDD
One DVDRW
One Floppy Drive
One Cooler Fan of 8cm diameter
One external USB Hub always connected to a USB port
One Keyboard
One Mouse
One Video card (512MB RAM), not the onboard one.
Two RAMs (1GB each)

Here are the specification, and Feature of the new PSU:

Specification:
Type: ATX V2.2 / 2.3 (EPS 12V 2.91 for 900W / 1050W)
Input Voltage: 100V~240V
Input Current: 550~750W: Max 10A; 900~1050W: Max 13A
140MM Exhaust Fan
Dimension: 150 (W) X 158 (D) X 86 (H)
MTBF: 100000hrs
Effecticiency: 80%
Hold Up time: >17ms
Power Good Signal: 100~150ms]

Feature:
20/24 Pin Mani Connector Available
Support The New 8(6+2) Pin PCI Express Connector
Support S-ATA II Tech., Up to 4(6) Connector
2(4) PCI-Express Connector
2(4) Independent Sets of +12V Output
2(4) Sets Over Current Protection (OCP)
Temperature Control Function inside

[hellnoire]

What's connected to the USB hub?

[kwfine]

What's connected to the USB hub?

The USB Hub has got 8 ports, and three of the 8 ports are used:
A 55-in-one card reader
A USB Fan
A Scanner

[hellnoire]

Can you try unplugging them and booting up? If so, I think one of them is drawing too much power. The other thing is, you could try plugging in the 24 pin, boot, if it doesn't work, use the 20 pin, or vice versa.

[Raymond]

I personally wouldn't try to use a 20-pin PSU to a 24-pin socket on the motherboard.
Computer randomly restarting can be caused by a lot of factors and it is the most time consuming task for a technician but very seldom it is caused by PSU. A faulty PSU would only cause the computer to power down and not restart.

Here are my steps to normally check the automatic restart problem.

1. Disconnect everything and run computer as bare as possible
2. Test RAM
3. Reinstall a clean windows

If your computer still restarts randomly after doing all the above, it is either your CPU or motherboard. I had a faulty motherboard before and it caused a LOT of problems.

[kwfine]

Many thanks to the help, hellnoire, and Raymond.

BTW, Raymond,
the one I asked for was a 550W, but as you can see it the specification that I have posted,
it stated that it will consume 1050W. So it is a 1050W PSU instead of a 550W one?

[bogdan_mihai58]

The Psu is ok....550 W is enough for almost every PC, i think the problem is that you put a 20 pin connector in a 24 pin motherboard....try putting an 24 pin PSU on the motherboard.... it should work

[chunky]

Am I right in what you are saying. The new PSU has a 20 pin connector and the motherboard has 24?
I have come across this before.
If you look at the plugs on the PSU you will probably find, that with many new PSU with a 20 pin motherboard socket there will be an additional 4 pin that mates with the 20pin so that it can also be used on a 24 pin socket motherboard. First look at the 20 pin plug and then look for a 4 pin that matches size wise. They are normally marked where they butt up to each other. The 20 pin plug can then be inserted to one end of the 24 pin socket and then the matching 4 pin plug can be inserted into the end 4. This then gives you the 24 pin socket required on the motherboard.