On/Off Switch Problem?

I'm helping a lady with her Dell Dimension 4600 computer (Win XP). Sometimes, after it's been off for awhile, especially after an hour or so, pressing the On/Off switch on the front of the desktop tower does not turn the computer on. The green LED is lit on the motherboard.

I have checked the connections, and wiggled the power supply plug.

What happens next is the problem: I keep pressing the On/Off power switch and then stop. After a short period (1 minute.... perhaps a bit less, a bit more) the computer, as if on its own, starts up, but it sounds as if it is alternatingly turning on and off, on and off, on and off, over and over, until I once again press the power switch, then it stays on and everything is fine.

Dell Support said I needed a new I/O Panel, but I wonder about the Power Supply and motherboard.

Any ideas?

PS. I forgot to mention, if the computer has been running, and I turn it off via Start button, I can go right back, press the On/Off button on the front of the computer, and it works fine. The problem is only after the computer has been off for some time, and that time varies.

Tom

 

Hi Tom,

Please in future don't "wiggle" connections, you can totally destroy a system by doing so.

From your post it sound's like it's a heating issue, not necessarily M/Board, PSU or fans but something isn't happy with warming up and cooling down.

If the PC's still under warranty then return it, if not it's still best to follow Dell's advice

 

Wildfire,

Thanks for the reply!! When I said wiggle, I meant I moved the 120V power cord back and forth to make sure it was seated, not the interior connections.

PC is not under warranty and while I do enjoy Dell Chat, I don't accept their word as gospel.

The thing that has me baffled is once it turns on, and it does it "on it's own" quite a while (minute or so) after I've pushed in on the on/off switch, the computer powers on and off repeatedly, until I push the power switch once more. I am hoping someone else has had this particular thing happen. I did a lot of searching for dead computers with MOBO light on, but saw nothing about this repetitive powering up/powering off issue.

Tom

 

Try replacing the CMOS battery. I have seen a few strange problems because of it and it's the first thing I check.

Disconnect any added hardware (take out any PCI cards, USB, etc). You can disconnect drives, even the HDD and see how it starts.

Some old models of Dells had rearranged connections in the motherboard power connector, you could test using another power supply, but put the model number (4600) and "power" into a websearch first and check through the hits that it is not one of the rewired models.

"I/O Panel ", that probably means a new motherboard. If it is not something simple, get the lady to think about her options. Repairs I expect, will be expensive. Ask them to give you a quote to replace the motherboard. [If she decides on a new computer, the old HDD could be put into an external enclosure so she could access her old data.]

Temperature...mmm...check inside the case when it is running, that all the fans are spinning freely.

Matt

 

A decent "upgrade box" is not very expensive. You can still use the same monitor, mouse, keyboard, etc. She would need to get a retail version of Windows (Vista?).

Matt

 

Matt,

Thanks for all the info! The I/O panel is the front panel that includes the On/Off switch. Dell doesn't stock just the switch for the 4600. I also ordered a power supply tester. If it's the motherboard, we will elect for a new computer

I will also get a new CMOS battery. Can't hurt!

Tom