Dead PC - not getting power

I have a Dell Diminsion 4600, service tag G2BH741, that won't power on. The woman who owns is said she got it as part of a divorce settlement. It has been in storage for two months (in the box on a crate). She said she is almost sure it worked prior to the divorce.

She said a friend opened it up and dusted it out, cleaned the system fan.

There is some power getting to the MOBO as I can see a green led at CR8j1 lit when it is plugged in.

Pressing the on/off switch on the front has not result.

My thought is the PSU is dead but would like opinions.

Mitch

 

Hello Mitch,

The first thing I'd suggest is replacing the CMOS battery - that's a small button battery on the motherboard - CR2032 is the most common but you can take a look when you remove the existing battery. This should cost you about $3.

Lets explain what might be going on and why this becomes a necessary first step. That little battery supplies enough power to the CMOS chip for it to "remember" your system hardware settings when the computer is not plugged into an electrical outlet. It remembers the size of your hard drive, the drive's geometry, the boot order of different devices, the processor and its speed, the type and size and timings of your memory, your video card, your IRQs or interrupts and how they are assigned. It remembers specific voltages required to operate a machine and all the other things necessary to boot up and run normally.

When power is removed from the system (its boxed and put in storage), that battery may not have enough power to retain or "remember" all of those settings. Then the machine gets unpacked and plugged into an outlet but it "forgot" all those things necessary to boot up and run. The net effect is exactly what you are experiencing. Now, one can clear CMOS by locating the small 3 pin jumper usually found in close proximatey to the battery itself and performing a very simple operation. First, unplug the computer from the wall socket and then unplug the main power lead (big 20 or 24 pin connector) inside the computer which is connected to the motherboard itself. Then move that little jumper from pins 1&2 to pins 2&3 - wait 10-15 seconds - move the jumper back to pins 1&2 and reconnect the main power lead to the motherboard. Now you can plug the computer back into an outlet and start it up.

Upon startup, start tapping the delete key or whatever key designation shows up on the screen to enter Setup. This should get you into the BIOS and permit you to setup your machine's configuration. If this is all foriegn, you should at least be able to select a default setup and save those settings upon exit. You can also consult your manual for guidance on custom setup options or seek professional assistance but this procedure should permit you to boot the machine once again.

Let us know how you make out.


edit: more - you should be able to clear CMOS, enter BIOS on startup and reset things without replacing the battery, however, this will be a continually reoccuring problem if the battery is not replaced. So the recommendation is to replace the battery, clear CMOS and then reset the BIOS.

 

Rockster2U,

Thanks for the reply. I replaced the battery. Still not powering up but the green led on the mobo is lit when I unplug the PC the green led goes out. I have another pc here that works so I am thinking about swaping out the PSU just to see if that is the problem.

Mitch

Really couldn't find any info on the mobo so not sure what the green led represents.

 

Hi Mitch,
got to agree the manual for that system doesn't show the particular led you are talking about, but I would expect it to be the onboard power indicator, ie: do not disconnect ram modules unless board is grounded (residual power disapated),
Have you reseated the front panel I/O plug? (J9G1) and I'm not exactly sure what the control panel connector is about (J2J7) but I would reseat it as well.
regards
Jac

 

Most fundamental question is .............. did you clear CMOS and reset BIOS? Unless/until that's done, I would expect no change to anything.

 

Yes, cleared/reset bios. Checked all connections - all re-seated. Lights on network adaptor work as well, so there is power getting there.

Battery replacement was not with a brand new battery but one I had from a previously known to work computer. Going to buy a NEW battery tomorrow just to be sure.

Will report back then.

 

If there is power to the board, but it doesn't power up when the on/off button is pressed I would assume there is a fault with either the power button, wiring or the solder joints on the board
Jac

 

let's hope it's a wiring problem. I'll keep plugging along until I find the culprit.

I'll keep y'all posted. And welcome any advice/suggestions.

 

Update, so far

I disconnected everything from the mb. I tested the powerswitch connector with an ohm meter - has resistance at least when switch is depressed. some connectors were impossible to check (just too darn small).

I checked the male connectors on the mb. Pins show some resistance so I will assume they are communicating with the mb properly.

All said, the problem must be on the mb. I did talk to the owner and asked if it had ever been dropped - she didn't know and since her divorce was not a pleasant one she can't ask her ex.

She did add that when her friend was helping her dust it out, she (owner) used a tooth brush to clean the area around the front I/O, USB ports [there is an opening at the bottom of the front cover - she stuck the toothbrush up there]. She also said a cloth was used to clean/wipe out the dust. I think that will probably explain the problem

Guess if I had a Post-Probe (don't know if they're still around) things would be easier.....{googled it - they still exist - not going to buy one for one PC though}

Any suggestions/ideas welcome.

 

You can yank the video card if its a seperate card. You can also yank the memory. Then clean the contacts of both using a pencil eraser wiping down, not across. Then clean the contacts with a Q-Tip dippied in alcohol, let them dry and put the video card and memory back in, making sure they snap into place. If its on-board video, do you have an extra video card you could try?

 

Thanks, I'll do that. I do happen to have a spare video card. Will mess with that later today. Just got home from work - better get sleep before I start messing around in the computer. Will report back this evening.

 

Well, still nothing. I cleaned the contacts on the RAM and put in a video card I had in my "extra stuff" drawer but still get absolutely nothing when I depress the switch.

 

Houston, we have a problem. Well, I'm at a loss here for any kind of quick fix. reviewing what you've already been through, I guess the remaining possibilities are Power Supply, motherboard or CPU. and I'm not sure this warrants spending time or money on fixing. Thats a decision you are going to have to weigh carefully.

 

I agree. The owner doesn't want to spend money on it because of its age. For a few dollars more she said she could get a basic Emachine at Wally World.

Thanks for all the help, suggestions, and advice.

Mitch