It's dead Jim, PC help required, others may also opine.

[Beest]

So,
Dell Inspiron desktop PC, a couple of years old, will check.

Major symptom no activity, press the power button nothing happens, no lights, no sounds, no fans, nada.

On the back just below the power cord is a green LED that lights with cord plugged in and goes out after about 10 seconds when the cord is pulled.

I have opened the case, when the power is plugged in a single small orange LED lights on the board, it is constant, no flashing etc, also goes off after about 10 seconds when cord is pulled.


Secondary sypmtons: on a couple of occasions in the previous weeks it would be slow to wake from hibernate or low power mode. Blue power light and the drive activity light would be flashing but nothing on the display. Holding the power button to power off, then turning it back on, it would take a couple of minutes to wake up, but be fine after that, I blamed this on one of the kids having lot's of youtube and flash games left running when it powered down.


I was hoping it was the power supply, but I guess the orange light on the main board means there is power to there.

I tested that the power button the front was working, seems good.

I see the coin cell on the main board, might this be bad, should I pull it and test it or replace, would it's failure produce this kind of problem. I've had two major pieces of equipment go down at work because the battery of the main board went.

What else to do, things to test or look for. Could it still be the power supply, I understand this would be easy to replace.

I'm asking here first, to give everyone a chance to ruminate, then I'll go and search the internet and dell for help

Thanks

EDIT: purchase date 3/19/2009, just outside 3 years

I tried removing and reseating the memory and hard drive as per Dells guide, no change.

I tried unplugging the psu cable at the motherboard and jumping the green and black wires with a safety clip as suggested in a couple of places. The psu fan came on and it sounded like the hard drive span up too. Seeing several identical problems, one with a similar build date, with no resolutions, sigh, looks like the motherboard

[jimhelm]

the power switch is cocked

edit. having now read that entire post... nevermind. that does sound mother board ish.

[zippyt]

try a power supply first , they are cheap , $50 ish or less ,
if that dont work then well,,,,,,,,,,,,,,

[Gravdigr]

Originally Posted by zippyt

try a power supply first , they are cheap , $50 ish or less ,
if that dont work then well,,,,,,,,,,,,,,

,,,,,,,you'll have an extra power supply.

[Beest]

hor universal are power supplys, we have an old, 2001, dell desktop upstairs, could I at least plug it in to see if it works, even if it wouldn't fit in the case?

[ZenGum]

No reliable answer, but if it isn't compatible, you'll burn out something which is probably important.

But it's probably broken anyway, right? So, why not?

[tw]

Originally Posted by Beest

Major symptom no activity, press the power button nothing happens, no lights, no sounds, no fans, nada.

You have two choices. Use wild speculation to keep replacing good parts until something works. Or follow the evidence to know what is wrong immediately before replacing (or disconnecting) anything. Obviously the latter costs much less money and is faster.

First, it is a Dell. So it has four diagnostic LEDs. What do those report?

Second, buy or borrow a multimeter (even $5 in Harbor Freight or a little more in Wal-Mart). The spend about 1 minute to obtain numbers from six wires should you choose that option. A next post will identify the suspect without doubts. Or eliminate over 95% of current suspects.

If you do part swapping, then the problem may be complicated.

LED says nothing about the supply. It only says AC mains power exists. And that damage can result if you make any computer changes when that light is on.

[tw]

Originally Posted by Beest

I blamed this on one of the kids having lot's of youtube and flash games left running when it powered down.

No software can cause hardware damage. Swapping parts is a many times greater threat to hardware.

[BrianR]

how about telling Beest which wires to read? I am following since I have a computer with the same problem, other than it's NOT a Dell.

[monster]

Originally Posted by tw

No software can cause hardware damage. Swapping parts is a many times greater threat to hardware.

1. Note the past tense.
2. Note that he wasn't saying he blamed the hardware failure on that, but the sluggishness prior to the hardware failure.

The rest of it seems sound advice to me, shame you have to coat it with this sort of stuff. If I'd been in, I'd've baulked at him pulling it apart. But I wasn't.

[tw]

Originally Posted by BrianR

I am following since I have a computer with the same problem, other than it's NOT a Dell.

Once the numbers are obtained, then the problem can be defined. Procedure was posted in Power supply problem? .

[Beest]

Originally Posted by tw

Once the numbers are obtained, then the problem can be defined. Procedure was posted in Power supply problem? .

Originally Posted by tw

Measure a purple wire from PSU where it connects to the motherboard. It should read about 5 VDC. Report that number to three digits.

Measure the green and gray wires both before and when the power switch is pressed. Report those 3 digit numbers.

got my $5 Harbor freight meter.

I see the purple green and grey wires, but where do I put the other lead to the meter, ground ?

On the inside there is only one solid orange LED, at one corner of the motherboard, if there are other LEDs they are not lit.

Since this is the secondary/kids/backup computer I have time for diagnostics.

[Gravdigr]

Originally Posted by monster

If I'd been in, I'd've baulked at him pulling it apart. But I wasn't.

Originally Posted by Beest

I have time for diagnostics.

Careful. (The boss is right behind you...)

[Beest]

Black is ground, duh, lot's of blacks all the same ground of well.

5.02V on purple

3.45V on green

0V on grey

[tw]

Originally Posted by Beest

5.02V on purple
3.45V on green
0V on grey

So far, good. The black probe could also be connected to the chassis.

Now follow those directions. Measure the green and gray wires both before and when the power switch is pressed. Note the behavior on each wire as the power switch is pressed.

Obviously the system will not load and execute tasks. Whereas that third step is valid for BrianR, it is different for you. What does any one yellow, orange, and red wire do when the power switch is pressed? For example, do each start to rise and then fall? Does any one not move? Or do all not do anything?

Diagnostic LEDs are not inside. From one Dell service manual: "your computer is equipped with four lights on the back panel labeled "A," "B," "C," and "D." These lights can be yellow or green. When the computer starts normally, the lights flash. After the computer starts, the lights remain green. If the computer malfunctions, ..."

To say more unique to your system requires the Service Tag number. Often a label somewhere on the side or back of a Dell Desktop. And often found on the underside of laptops.