No power to my computer

[meckeard]

Hi,

I just assembled a new PC. When I turn on the power, nothing happens.

I checked all plugs to ensure they are in the right place and sitting correctly. I checked the power cord. I even went backwards and removed each piece within the PC 1 at a time and tried. No luck.

The case is brand new. But, could it be the power supply or switch. If so, how do you test them?

Any suggestions?

Thanks,
Mark

 

[ramani]

HI
Your problems are not fully explained.
1. Is your power cable from CASE to MotherBoard securely connected.
2. Is you computer case (If ATX) power switch connected to motherboard at its correct place.

3. If your case is proper, try inputting the power cable to the monitor directly, to see if that is getting ON... then.. power is available..
Now connect the power to the case. Do you notice any movement of the cases power supply fan. If yes, there is a power input. Did you notice a similat movement in the CPU fan. Power is getting upto motherboard. Is there any led lighted when motherboard gets power. Most of the newer motherboards have an LED for RAM power presence.

4. The power will not get on.. if...
a. The Floppy cable is connected the reverse way. To check that, remove the floppy cable and start the power.
b. If CD cable is reverse... do a similar exercise
c. Harddisk cable is reverse connected.. do a similar exercise.
OR
remove all these cables.. power up and the connect one by one to see if you are on the right direction.

ALWAYS REMEMBER TO POWER DOWN AND REMOVE POWER CABLE BEFORE ADDING REMOVING CABLES/CONNECTIONS IN THE MOTHERBOARD OR TO COMPONENTS.
5. Is your RAM scurely placed in its slot.

Never assume you have done that correctly. Observe one by one. YOu are syre to succeed or identify the problem.

Hope you get the solution.

ramani :-9
(Subramanian.G),FoxAcc, ramani_g@yahoo.com

 

[carmatt]

meckeard,

ramani gave you a terrific troubleshooting list and may have left something out. power supplies have two different voltage settings. check and make sure you are using the 115v settings

 

[meckeard]

Hi Ramani,

Let me elaborate:

1. I checked the power cord with my old PC. It's fine.
2. I unplugged all the IDE cables, one at a time. No luck.
3. I removed the video card. No luck.
4. I checked the main connection from the power supply to the MB. It only goes in 1 way, but it's fine.
5. I removed the RAM. No luck.
6. I checked all cables, they seem to be in place.

When I try to power on, NOTHING happens. Not a sound.

Thanks,
Mark

 

[edfair]

Since power only goes one way, it must be ATX. Down and latched?
Have main switch on the PS? When it is turned on some power should apply to the M/B. Then front power switch should bring the rest up. You could short the power up connectors on the board to satisfy curiosity of whether power on switch is possibly bad. Ed Fair
efair@atlnet.com

Any advice I give is my best judgement based on my interpretation of the facts you supply.

Help increase my knowledge by providing some feedback, good or bad, on any advice I have given.

 

[Guest_imported]

Not sure how our friend above knows you're on 115v AC mains but...!

If you have access to a voltmeter, try checking between pin 14 (usually GREEN wire) and earth (pins 3,5,7,13,15,16,17) of the multiway power plug when the PSU is attached to the motherboard. Should show about 5 volts DC, and go down to zero when the front panel POWER-ON button is pressed.

ROGER - GØAOZ
(U.K. = 230v AC mains).

 

[ramani]

HI
If you are doubting the power wire connected from switch to motherboard...
for a change.. connect the reset wire to the power connection on the motherboard.. and treat the reset switch as your power switch.. (IF ATX CASE). so when you press reset, the power shall start. If that is the case, may be there is a cut in the power wire between the switch and the motherboard ramani :-9
(Subramanian.G),FoxAcc, ramani_g@yahoo.com

 

[ramani]

HI
Yet another posibility to check...

Some motherboards dont start first time, since the BIOS contains some old data not suitable for start up.(Even if a new board).
So SET the motherboard jumper to clear the BIOS. When you do that, first remove power from outlet..., set the jumper to clear... then connect power.. start.. (though nothing startsup)... wait a few seconds.. say 5 seconds.. then put off.. remove power cable.. put back the CMOS jumper.. and then start as usual..

SOME MOTHERBOARDS SPECIFY.. keep pressing HOME key to reset.

Try your luck ramani :-9
(Subramanian.G),FoxAcc, ramani_g@yahoo.com

 

[swayda]

I have had the same problem with two motherboards, three cases and four power supplies. I can only tell you what I have found out.

If the power is on the ps fan will turn unless it's a thermostatically controlled fan which I have never even seen.

If you're not getting any audio signals when you turn the computer on I have found it means

1. You may no be making good contact between the power connector and the motherboard. Make sure the connection is solidly in place.

2. The CPU could be dead.

3. The motherboard may be dead.

It took me a long time and effort just to find out those few things.

Reversed data cables will not result in no post. You'd simply get an error message when your BIOS queries the drives. A bad graphics will result in one long and three short tones. A mistaken jumper setting or faulty chip other than graphics would report with one long tone and one short. The test mentioned for the power test is correct but I don't know how you can test for the second part since the power connector has to be off the system board so when you press the on switch nothinbg would happen unless you open the insulation to get to the wire. I finally reached the point where I bought a motherboard-chip combo and worked backward from there. Don Swayser
swayser@optonline.net

 

[meckeard]

Hi All,

Thanks for all the tips. Even though I found the problem to be different than all that was posted, the feedback was incredible. Ecspecially since I will be buidling another PC in about 1 month.

Oh yeah, my problem. On the back of the case, near the very top, is a small switch. It seems this switch is an on/off switch for the power supply. It came in the "off" position. I have never seen a case where the power supply had an on/off switch before. So, w/o thinking much about, never considered it. However, after reading many posts to my original question, the switch came to mind. I went home and flipped it, and it turned on.

Thanks for all who responded.

Mark