Power supply or power switch?

Question

I have a Dimension 2400 that I have had intermittent trouble with.  On several occasions, I would press the power button several times to get the system to power up.  Now, it does nothing.  I have a green LED light on the MOBO.  As I have read in several other posts, I tried unplugging everything from the MOBO, still nothing--no beeps--no fan power--NOTHING. I reseated everything--still nothing.  If the switch is bad, I am guessing that using a jumper wire on the PSU will not work, or will it?  I really don't want the hassle of going through buying a PSU, then switch, and then find out the MOBO is bad-- would rather just buy a new system.  HELP!!!

shesagordie · Answer

grifbeck

If you are handy around computers, you could test the power supply by unplugging the 20 pin connector from the motherboard and jumping the Green wire to one of the Black wires, if power supply and/or case/processor fans run, then you know it's good.

Note= Do not remove any wires from the plug, use a small piece of wire or a paper clip as a jumper

Or, you could buy and use power supply tester, similar to the unit shown here,

http://www.cwc-group.com/pojuatxposut.html

Bev.

grifbeck · Answer

OK. I ran the jumper from the green to black on the MOBO power source from the PSU.  The fan on the PSU did run.  Does this mean the switch it most likely the culprit?  I know there is the possibility of the MOBO being bad itself, however, I'd rather be optimistic.:smileyhappy:

shesagordie · Answer

grifbeck

My money would be on the motherboard.

Does the case fan on the back panel run, also?

As the Power supply supply has checked out, then reconnect the power supply to the motherboard, remove all the PCI cards, video card [if installed] and memory, disconnect the all IDE and FD data cables, check that the front panel cable is connected to motherboard, with nothing else connected to the case, except the power cable, then power the system on. If you do not get any beep codes or no LEDs in the back, then it would appear that motherboard has died.

Bev.

Message Edited by shesagordie on 07-29-200608:40 PM

grifbeck · Answer

Looks like the motherboard has died. Would that also explain previous problems with it starting up? Also, how to I identify exactly what board this is. I want to switch it with as little headache as possible.

shesagordie · Answer

grifbeck   It's a Dell motherboard, with proprietary features, the easiest procedure would to use the same D-2400 board.   You can buy a replacement by calling Dell Spare Parts @ 1-800-449-3355 option 4, M-F 7 to 7 CDT and have the system's 'Service Tag' handy.   Browse eBay, this may be the cheaper option.   or for $69.99 free S&H from here,   http://www.ascendtech.us/index.asp?FSCat=303&url=IND&iFromFeatured=1   Bev.

shesagordie · Answer

grifbeck wrote: '.... I do have a green light on the power switch and a blinking amber one'  ? Does the case fan run? If the power button LED is blinking amber.  Unplug the power cord, open the case, check all the cables by removing and reseating them.Bev.

grifbeck · Answer

Bev,

I replaced the motherboard, now I still have no power, but I do have a green light on the power switch and a blinking amber one. I do not have the (4) LED lights on the rear panel and have been unable to find any codes for the power switch lights. Soooooo, now what?

Thanks.

shesagordie · Answer

grifbeck   Where did you buy the motherboard?   Bev.

grifbeck · Answer

Nothing runs.  The PSU fan will run if I use a jumper wire.  Nothing runs otherwise. Haven't had a chance to recheck all the connections though.  Computer is my Mom's -- 30 miles away.:smileyhappy:

grifbeck · Answer

From Ascend Tech at the link you sent.

grifbeck · Answer

I have checked all the connections to the motherboard -- all secure. I still get the same thing. I get a green harddrive light as soon as I plug the unit in (as well as the "flea" light on the motherboard). If I press the Power button the amber power light begins to blink. Any suggestions?

Thanks in advance for your help.

shesagordie · Answer

grifbeck   Either take the power supply to a local computer store and have them test it or buy a power supply tester [like the unit shown here] and test yourself,   http://www.cwc-group.com/pojuatxposut.html   Bev.

grifbeck · Answer

I ordered the power tester.  Got it in and tested the unit.  PSU seems to be fine.  Now what?

grifbeck · Answer

Bev.

Do you have any further suggestions for this machine? (OR anyone else for that matter) I am really at the end of my expertise. I tried to contact Ascend Tech and they replied to my email with a phone number which I get no answer to and I also get no return from my messages. HELP!!??

grifbeck

hansjorn · Answer

Hi grillbeck,

You and I seem to have the same problem - although I have only come to the point of having replaced the motherboard on my Dimension 4550.

I was adviced by a Dell technician, who via telephone directed me through the same passes, as you are telling about.

Except for the power-supply, which he didn't consider to be broke. But then .. I have not tested it or replaced it.

My suspicion is, that it has something to do with the soft power-button on the front and/or the connection from there to the motherboard.

I cannot get at it - I don't know how to get the front off these new Dell cabinets, but from my experience with older Dell Dimensions, if we took the front off and got right to the button, where you actually start the machine, we could circumvent it and get it working.

At least we could get a signal from the motherboard to see, what was the trouble.

But not on this machine - it is totally deaf and blind - I have never seen anything like it.

And I must say to Dell, that they should list this problem and give some advice/help to new-comers - since a Google-search revealed, that it happens quite a lot. But the manuals doesn't say a thing about a machine having this state.

It is like calling Dell Support by phone, and then they say: We are open from 8am to 5pm, and since we are closed now, please use our Tech support on the Internet ;-)

Very good indeed since we have a machine, maybe the only one around, which has died and cannot reach the Internet.

So please put it into your written mini-manuals as the worst case scenario and tell people how to check for the most elementary signals - like a dead power-supply - what the little green light on the motherboard indicates, what voltage should be on the many colored "things" coming out from the power-supply etc. etc.

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Power supply or power switch?

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