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

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 :(

the power switch is cocked

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

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.:o

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?

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?

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.

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

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.

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.

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

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.

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

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

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.

Not sure how I'm going to test the voltages plugged in yet, I guess I'd have to contact on the solder ends on the other side of the board, whihc would mean a more major dissassembly job. I'll put some more thought into this.

I don't think there are external indicator LEDs on this model, maybe older or higher end models, think of the cents they save by not including them.

I see some models used the keyboard caps lock, num lock light as indicators, but not mentioned in the manual for this one.

At this base model it's barely worth changing anything but the power supply, certainly not to pay a professional to do it.

Dell Service code: JJ8FJG1

Maybe the notification LED is the power switch itself. It means different things if the lamp in the switch is off, blinking or steady amber, blinking or steady blue.

http://support.dell.com/support/edoc...g/MT480A01.pdf

No light.......

The previous post said: How did you measure the purple wire (5.02 volts)? Only one place to measure it. Push the meter probe into that nylon connector to touch a wire inside that connector. Do same for all other measurements.

Again, if not clear. Disconnect, remove, or disassemble nothing (other than the cover plate). Disconnecting or removing can make a problem more complex. If also not stated earlier, disconnecting sometimes can create more damage.

The entire task should take as little as 60 seconds. Touch the probe to each wire where it connects to the motherboard. Record those numbers and behavior. Post numbers. That's it. Most time should be spent posting those numbers.

Was this Inspiron 518 purchased in Best Buy? If those critically important Diagnostic lights are not on the front panel, then that MBA attitude says why. Best prices for a Dell means purchasing direct from Dell. Have seen too many products (even HP printers) missing essential functions to meet Best Buy's 'increase our profits at the expense of the customer' attitude.

From the Technology Guide for your machine: BTW, two updates have been available for Inspiron 518 after you purchased it in Mar 2009. One was a recommended update for the video display. The other was a critically important updatda for serial ATA. Enter that Service Tag into the Dell website (under Product Support) to learn more.

Yes, the power button is an indicator light, blue solid or flashing for asleep or awake, never seen it be orange, as said now nothing.

System was purchase direct from Dell.

I measured the voltages I did by pulling the plug and putting the probes in that end, I'll see if I can slip them down the side to get a reading while still plugged in.

The only other light on the front in normal operation is the drive light.

Don't slip a probe. Saying again. Jam that probe inside the connector hole for each wire. Disconnect, disassemble, or remove nothing. Do not even move a connector. Jam that probe in with aggression. If the probe is bigger than the hole, then wrap a paper clip onto the probe and stick the paper clip end into the hole. But, if not clear before, absolutely do not move, partially move, disconnect, disassemble, or remove anything (but the already removed cover plate).

That was pretty straight forwardm ny $4 Harbor freight meter has noce pointy probes.
So with everything plugged in as in the wroking state

All the red wires I measured were 0.01V power button on or off,

all the single orange wires were 0.03V power button on/off

There is a single socket with both orange and brown wires in it, this read 0,01 power button on/off.

The grey wire was 0V power button on/off

The purple wire was 3.38 V but dropped to 3.37 when the power button was pressed.


The green wire, the first time I measures it at 2.23V power on or off, when I measured it again after looking at the others it was 3.21 then dropped to 3.19 when the power button was pressed

about an hour later, with the system left plugged in while I was on a call it is reading 3.24 power on/off, this small difference could well be variation in my chepa meter though I guess.

OK. First, a PSU is actually multiple power supplies. Purple wire connects a special voltage constantly and only to certain motherboard functions. That voltage is why all computer work must be performed with the AC power cord disconnected. Otherwise damage can result. That LED on the motherboard was also making the same warning. Only work on a computer when that LED eventually dims out.

Purple wire voltage (5VSB) is defective. Therefore a power controller cannot power on the system. However, the question is why? Is the motherboard shorted or is the PSU purple wire power supply defective?

Well, you measured the purple wire when disconnected from the motherboard at 5.02 volts. That only says it may or may not be defective.

Subsystems powered by the purple wire. Anything that might 'wake up' the computer including the keyboard, modem, and NIC. Also the Front I/O Panel is powered by the purple wire. It can be temporary disconnected where it connects to the motherboard.

In your BIOS setup would be a more complete list of those devices that can wakeup the machine. So, with AC power cord disconnected, remove any peripheral (ie USB device, modem card, keyboard, etc) that might be excessively loading the purple wire 5VSB. Reconnect the PSU to AC mains. See if that purple wire voltage rises up to about 5 volts. If yes, one of those removed devices might be defective.

We clearly see the defect. 5VSB (purple wire) well below 5 volts means the power controller cannot tell its power supply to power on. And cannot even let the CPU execute (power controller tells the CPU when it can work).

The green wire is the power controller telling the PSU to power on. But your numbers on the green wire confirm defective numbers from the purple wire. Therefore the green wire cannot go to near zero volts when the power button is pressed. Therefore the main PSU power supply is never told to power on.

Some will recommend jumpering the green wire to any black wire with a paper clip. In your case, the PSU will probably power on. So they will conclude the PSU is good. They would be confused. The meter says 5VSB - the other supply - has failed. Their 'paper clip' test would never see the defect. An example of why so many get confused when using observation rather than using a meter. An example of why the meter so quickly cuts through confusion.

Now, moving on to fixing it. The fault could be on the motherboard side or inside the PSU. If removing those other devices does not restore 5VSB. Then let's try any other test. After removing the AC power cord, then disconnect all PSU power connections to the system. Connect another PSU to that 24 pin connector (where you made measurements). Any PSU (even an undersized one) that has a similar 24 pin connector is sufficient. The second PSU need not even be in the system (if its wire is long enough to connect to the 24 pins on the motherboard).

Connect that second PSU to AC mains. Measure the purple wire voltage. It must be greater than 4.87 volts. If yes, then the first PSU has a defective 5VSB. If no, then the defect is somewhere else in your system (probably on the motherboard).

A second possible test. Again with the PSU disconnected from the motherboard. Buy some 100 ohm resistors from Radio Shack (maybe $1). Stuff maybe all four resistor leads into the purple wire connection hole. Connect the other end of those resistors to any black wire hole. Connect the PSU to AC mains. Measure the purple wire to black wire voltage. If not 5.02 (as before), then the 5VSB supply is defective - without doubt. If it is about 5volts, then the 5VSB supply 'might' be good. This 'load test' is a best option.

Or a third option. Buy a new supply. Connect it. Confirm the new PSU can provide sufficient purple wire 5 volts. Let me know if you choose this third option so that details can be provided.

Apparently the main supply inside the PSU is good. But a tiny 5VSB supply has either failed or has been shorted out by something on or attached to the motherboard. (Shorting out any supply does not harm that supply.) Above should help define which of two is defective. And says why the blue front panel light stays on constant.

Appreciate how much information was in those few numbers.

No external devices have been connected, keyboard etc.

So I disconnected everything I could from the motherboard, optical drive, disk drive, video board, memory card etc.

Plugged in mains, green wire tested 2.23 and purple wire 2.34, no lights on the front power button.

Plugged all those peripherals back in, voltages still the same.

I don't have a 24 pin PSU too try, i do have a 20 pin, the green purple and grey wires are all in the same place, almost all of the other wires are the same. one of the red wires on the 24 is white on the 20.

I saw the paper clip test early in investigations, it does make the fans power on.


I found some 600 ohm and 1K Ohm resistors lying around and tried plugging them into the purple wire, also 2 in parallel, no voltage drop.

I look for some 100's

As you may have already seen, a defective supply can act good when not connected to a load. That is why the paper clip test says so little useful. That is why power supply testers are almost useless. That is why a power supply is best measured by not disconnecting a single wire.

The 5VSB should output maybe 2 amps (its label may say more). A full load is 5/2 ohms or 2.5 ohms. Radio Shack may still sell 10 ohm 10 watt ceramic resistors. One of those might be easier to use than four 100 ohms in parallel (25 ohms).

5 volts divided by 10 ohms is a half amp. If the 5VSB is defective, then a half amp load should cause some voltage reduction.

If those 10 ohm resistors are sold in pairs, then two ten ohm resistors means a full 1 amp load. A great test of the 5VSB. Those two 10 ohm resistors (that will get hot when held) should not cause the 5VSB to drop. If 5VSB does drop, the PSU's 5VSB (and not anything in the PC) is defective. That is a definitive and "you have found the problem" conclusion.

5 volts divided by 25 ohms (four 100 ohms in parallel) is 200 ma. Not a great load. But enough that can be purchased cheaply. The ten ohm ceramic would be better but I don't know if it remains available.

600 ohm or 1k ohm resistors are only 10 milliamps (only one LED) or 5 milliamps (less than 1 LED). Virtually a near zero load.

If the PSU 5VSB does not drop with that load, then the problem (excessive load) is probably located on the motherboard.

OK,got it.

Thanks for all your help with this.

Yes they do.
Purple to black
no load 5.02V
10 ohm resistor 1.26 V
2x 10 ohm in parallel 0.82 V

The green light on the back of the power supply dims out when the resistors are connected.

I tried the same test on another PSU I have borrowed (20 pin connector), minimal voltage drop with this test.

So is that definitive on the PSU ?

So its the power supply like i initially said ???

LOL, yeah , thought you'd get akick out of that.

:p:

lol

get a bigger one , as in if it was a 250watt get a 450 , More POWER !!!!!!!
Oh and make sure it has Leds in it so it will look cool at nite !!!!

Yeph. That type of failure is typically a manufacturing defect. The defect may have existed many months ago. It was not a switch. A coin cell battery. Heat. A surge. Mishandling. The wife. Mystery currents from the plug. Failed motherboard. Defective BIOS. Bad CPU. Undersized video card. Intermittently getting loose wire. Dust. Undersized supply. Defective disk drive. Stuck fan. Or many suspects blamed on wild speculation to justify replacing parts. Another part of the supply that more often fails did not fail in yours. You had a failure of a tiny supply that should rarely fail. Sometimes, that entire 5VSB supply is only a single integrated circuit. A part that typically costs about $0.90.

Now, replace the supply. Ignore all discussion about watts as taught by advertising, hearsay, and A+ Certified computer techs. That supply should list an amp numbers for each voltage. A replacement supply must meet or exceed each DC amp number.

Of course, a new supply must have similar connectors, screw holes, and dimensions. Those dimensions are usually industry standard. Most important are ampere numbers for each DC voltage. Simply meet or exceed the number for each DC voltage.

A supply costing less than $60 is typically missing essential functions. That does not say a greater than $60 supply is better. That only says anyone selling a supply for $40 should be selling it for near zero profit. Or the supply must be missing essential functions.

When installed, one simple test will confirm the new supply is not defective. A defective supply can still boot a computer. But about one minute of labor quickly identifies some defects before its warranty expires.

any suggestions on where to look, or good brands?

$49 for a refurb, no detailed voltage info.
http://www.discountelectronics.com/i...detail&p=13852

or
http://www.amazon.com/Original-Genui...N%3DB005W39F7O

new egg .com has some good prices

Newegg was one of the first places I went, but they are not replacement slisted as compatable with my PC, I have to figure out which is the right one.

This one has 1000's of postive reviews and won some sort of award, but ahs a 20+4 pin connection, not 24 like mine, does this mean it won't fit
http://www.newegg.com/Product/Produc...82E16817153023

Newegg specs do include currents, so will ahve to look what's on my old one, guess I can take this out now.

This is the hot deal right now, still has a 20+4 pin connector.
http://www.newegg.com/Product/Produc...s-_-17-139-027

When I got a new power supply, I just took the old one down to Best Buy. I walked over to the help desk guys and asked if the one I had selected was compatible, and they let me open the box of the new one and compare the size and the connectors. There were a couple extra connectors I didn't need or use, but it works great.

I'm sure Newegg is cheaper.

I crowd sourced this on one of the big paintball boards, lot's of paintballers are also uber geeks.

Several recommendations for Corsair brand.

http://www.newegg.com/Product/Produc...82E16817139026

The advantage to Best buy is you can see it's the same size with the holes in the right places.

Exactly. You want the fan on the correct surface so it doesn't wind up pressed against a neighboring component that blocks off the airflow. You want the outlet and any switches to be lined up with the holes in your case, although you can cut holes into your case as needed.

I seem to remember paying $70 for mine. Your $45 is a better deal if it fits. But for me, paying an extra $25 to open the box before purchase and be certain it will work and will only require one trip to the store is not anything to look down your nose at. YMMV

Some disassemble computers to sell the parts. On Ebay, you may find the exact same supply for less money.

Indeed, used allegedly working oem parts $25-$30 shipped.

http://www.ebay.com/sch/i.html?_nkw=....c0.m270.l1313

hmm.

Ya get what ya pay for, I Hate Used "Working" electronic parts , they all ways seem to fail

I don't. Most electronic parts fail with infant mortality. Beyond infant mortality means failures are infrequent to virtually non-existent. Of course that is for the type of electronics. Semiconductors do not wear out. Mechanical can wear with age.

Those Ebay offers are a best solution as long as the seller has a good reputation.

Yeah, Posting from it now.:thumb:

I bought the new egg one, exceeds all the specs. , a bit of an offer and rebate will actually make it less in cost
If it makes it to the deep end of the bath tub should be a good deal.

Now, confirm the new supply really is good. Normal is for a defective supply to still boot and run a computer.

Repeat the previous multimeter procedure to obtain those three digit voltage numbers. However, before measuring the red, orange, and yellow wires, first setup the machine to actually see a supply defect.

IOW download from the internet, while playing complex graphics (ie a movie), while searching the hard drive, while powering some USB devices, while reading a CD-Rom, etc. When the system is multitasking, measure any one red, orange, and yellow wires. Then report voltages from the six wires to see if the supply is sufficient. So that the defect need not become obvious after its warranty expires.

Bit of a challenge where it's sighted but I'll give it a go.

I tested the green grey and purple, with it just on , bit nothing much else happening. green was low - 0.02 V, purple and grey 5.02 V

Those numbers could not be better. Healthy. More informative would be red, yellow, and orange wires when fully loaded by multitasking. Do that when convenient - or to solve insomnia.

DVD playing in one window, netflix streaming in another and doing a backup of monsters laptop.

task manager started 80 - 90 % but reduced to 40 -60 voltages dropped a little as activity dropped.

red 5.04
yellow 12.20
orange 3.33

Numbers report that each voltage provides sufficient current. Ripple voltage is minimal. IOW voltages looks ideal.

12 volt supply appears to be much larger than needed as compared to other voltages. That is OK. Just another fact suggested by the numbers.

Thanks

The supply was rated the same or higher max current at all voltages, since I didn't pay more for the privilage then, no problem.