Dell CPU won't power up

[wezsitat]

I've had my Dell 4550 for 1.5 years. A few weeks ago, I shut off the computer for the weekend. Monday morning I attempted to start up the computer and nothing happened. I took the computer to a "dell certified" technician and he told me I needed a new mother board. I bought the board, replaced it, try to power up and nothing happened. Since then, we've tried 3 new power sources and still no power.

Does anybody have any ideas as to what I can do to fix this piece of crap?

1 1W393 PROCESSOR, 80532, 2.53, 512K, 533, SOCKET N, C1
1 J0592 CARD (CIRCUIT), PLANAR (MOTHERBOARD), DIM4550, AUDIO/NIC, EPPID
1 7N242 KEYBOARD, 104, UNITED STATES, SILITEK, LOW COST, MIDNIGHT GRAY
1 6U220 KIT, MOUSE, PERSONAL SYSTEM 2, S69, LOGITECH
1 8T913 DUAL IN-LINE MEMORY MODULE, 128, 333M, 16X64, 8K, 184
1 5H175 CARD (CIRCUIT), GRAPHICS, NV17, FULL HEIGHT, DIMENSION
1 X0769 HARD DRIVE, 30G, I, 7.2K, 60G/P, HIT-VAN2
1 4T139 KIT, SOFTWARE, QIKN-NWUSR-ED-2K2, ENGLAND/ENGLISH
1 4Y427 KIT, SOFTWARE, WP-PRDCT-STE10.0, V3, ENGLAND/ENGLISH
1 4W419 KIT, SOFTWARE, BRTNCA2K3, ENGLAND/ENGLISH
1 6W678 KIT, SOFTWARE, OVERPACK, WXPHSP1, COMPACT DISKETTE W/DOCUMENTATION, ENGLAND/ENGLISH
1 0X790 COMPACT DISK READ WRITE, 680M, I, 5.25" FORM FACTOR, 48X, NEC CORPORATION, CHASSIS 2001

[Detritus]

Make sure you installed the right number of stand-offs in the case so that the motherboard isn't shorting out.

[Heavencent]

Quote:

Originally Posted by Detritus

Make sure you installed the right number of stand-offs in the case so that the motherboard isn't shorting out.

Yeah, I was thinking the same thing, because I once had this problem. Im 90% sure this is your problem.

[wezsitat]

The motherboard came in one piece. I had to slip out the old one and place the new one in.

I'm not a computer guy, so I'm not even sure what "stand offs" are.

[Heavencent]

Stand offs are usually plastic little peices that resemble thumb screws. What they do is that they raise the motherboard like a centimeter off the case (Im talking about inside, when you try to install it) so that the back of the motherboard doesnt touch the case. It wont power up because you are basically grounding it to the case.

Try just plugging in the power cable from the power supply and the jumpers for the front of the case just like as if it was installed. But do this OUTSIDE the case (Protect it from static! Lay it flat on a wooden table or something. Nothing metallic). It should power up if this is your problem. If it still doesn't power up, then something else is wrong.

But like I said before, I'm pretty sure this is your problem, especially with a brand new motherboard.

[golfcart]

If you replaced the board with an identicle board, it shouldn't be a standoff problem.

Make sure the power switch on the power supply is on if it has one. It's gotten me at least once. Also check to make sure the power supply voltage is set correctly for your country. It's 110 for US.

Are the power supplies standard ATX format? compare the wire colors on the old power supply with the new one to make sure they are the same. If they are different, your computer uses a non standard power supply. Don't use a standard supply unless that is what it came with.

Try using a screw driver or other metal object to short the two pins that the power switch plugs into. Simply follow the two wires from the switch back to the motherboard from the front of the case to see where they plug in. If it powers up when shorted, you have a bad power switch.

Check the CMOS jumper. It's usually right next to the battery. Sometimes new motherboards are shipped with the CMOS jumper off. If that's the case, it probably won't turn on until it is set correctly. Compare it to the old board to make sure it's set the same.

If all that fails, unplug everything except for 1 stick of ram, power supply, processor, and video(if it's not onboard). If it powers up that way, plug each item in one at a time until it doesn't boot again. That will tell you what the bad part is.

Good luck

[askthiru]

alrite.. i have the same problem here... Its not a dell computer though.. Here is my problem... I have this old pc which was working fine till yesterday. I'm assembling a new pc for my dad for which I have a separate case, new mobo and new cpu. The only thing I did was remove the DVD RW from my pc and put it in the new one... I didnt touch my old mobo or cpu... Now I got my new pc working fine.. so I go back to my old pc and it doesnt power up at all.. The power led is on for like 2 seconds and the cpu fan runs for 3 seconds.. but thats all... I dont know how can a pc that has been working fine suddenly not power up.. its the same power supply I was using all these days... I havent added any new component (infact I have removed a dvd writer from it)... I'm confused because of this... Should I change my mobo now?? pls help

[mazdarx7-64]

Does it beep?? Also you need to start a new thread for your problem.

[askthiru]

no beeps.. i've created a new thread.. thanks...

[Bersie]

I have the same exact 1.5 year old computer. We kept ours on all the time at home, but once in awhile we would turn it off. After about a year we started having trouble starting it up. I would get it started by pushing & playing with the on/off button & it would finally start, push& hold in the button for 30 secongds or push it real fast a bunch of times. 2 months ago it shut off & wouldn't come on. I talked with Dell tech, they said it was the motherboard & sent me a refurbished 1 at 1/2 price $65.00. I installed the new one & still have the same problem. I called Dell back 12/24/2004 they think it is the power supply, so I'm going out to get a new power supply this morning & will try it, i let you know. I also checked with Dell about a new switch panel, which Dell says comes with the front USB port panel (the switch panel plugs into the front USB panel which plugs into the motherboard), but they don't have any in stock & are supposed to contect me when one's available. Anyway I let you know after the new power supply goes in.