hardware failure in a very old Dell Optiplex Gx270 SFF

 Nostra63

A Steady Yellow light, could indicate a device on the system board may be faulty or incorrectly installed

Check the sequence of the four Diagnostic Lights on the back panel.

The GX 270 Troubleshooter and Diagnostic Guide, is HERE

Are there any 'Beeps'?

Bev.

 Nostra63

Then it sounds like the motherboard is bad.

If you are comfortable working around computers, you could try the following:

Note: The only 100% method of testing a PSU, is to install a know working power supply.

Unplug the cord from the power supply, hold the power button in for about 15/20 seconds, open the case, unplug the 20-pin power connector from the motherboard and jump the Green wire to one of the Black wires, reconnect the power cord and power the system, if power supply's fan and the hard drive run, then the PSU should be good.

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

Power supply checks out and the system still does not work, again remove the power cord, hold the power button in for several seconds to discharge the residue power, reconnect the 20-pin connector to the motherboard.

Remove all the PCI cards, the video card [if applicable], memory, all peripherals, disconnect the data and power cables to all the drives, check that the front panel cable is connected to motherboard, with nothing else connected to the system, reconnect the power cable and power the system on.

If you do not get any beep codes and/or there is no change in the diagnostic lights, then it would appear that the motherboard has died.

Bev.

as said the four diagnostic lights on the back of panel are off no light on them at all.

I already disconnected all the hardware and connected again and nothing happens and no beeps at all.

Ok I will do that tomorrow since I will get a power supply from a friend who is working, and I will see.

Could processor problems give this error too, or is only motherboard? cause all the caps appear to be ok, I'm a bit worried to get a motherboard somewhere who is with caps issues, since this model was with that problem not this one. Could the anti intrusion switch malfunction? or be damaged?

sry for asking but  for what the intrusion switch and what does he do, since I remember to open the case because of the fan been doing to much noise in that night and cleaned the inside with air, any chance the intrusion switch be damaged. I don't know what he does but in some systems the switch just cuts the power if the case is not well closed, could this be the case? I didn't check that. But well I don't know what he does too.

But thanks for all your support till now :)

Nostra63

From Dell:

The Chassis Intrusion Detection Switch detects any intrusion into the interior of your desktop and provides an indication of the same.

This switch is activated as soon as the cover of your desktop chassis is removed and any access is made to the interior of your desktop.

It provides a simple way of informing the user if the loss of his valuable, sensitive and secret data was due to a physical intrusion of the desktop.

A mechanism is provided that turns on in response to the closing of the switch for providing an output; an indication device then provides a corresponding indication when the mechanism turns on.

Bev.

well I have done as you said, didn't try a new or working power supply, because my friend's one is fried :emotion-6: worst than any thing 

so I tried the steps you said, the fan in the power supply  works but no signal in the hard drive :emotion-7: all the rest keeps the same, it's possible the power supply is not giving enough power to run all? the light in the motherboard is yellow (standby), meaning there is power on the motherboard when the 20 pin connector is connected to the motherboard.

I'm going to  try  get a power supply somehow and test it.

Is there any way to know if the problem is from motherboard, or any device in the motherboard, without spend money in a new motherboard.

In case the power supply is ok.

Thanks

I will thanks, just going to look where to buy one :emotion-18: eBay is the best bet, I will post something when I have the info. Thanks for all till now.

greatly appreciated :emotion-2:

king regards

 Nel

Nostra63

I suggest trying a 'know' working power supply.

Bev.

Just one thing, I disconnected the 20 pin power connector from the motherboard but I didn't as requested I frogot to use the clip to short it between green and black.

I did it just now but when power it nothing happens no noises no fan,(disconnected from the motherboard) not even a light in the power switch, nothing at all.

I turn off the power supply and discharge any remaining power and connect everything (motherboard) and power it on and comes as before yellow permanent light in the power switch and the noise of fan working really slow.

Sorry about the mistake. 

Since electricity and me don't goes well I miss that of the jump the power connector. my bad :emotion-10:

Nostra63

To check the motherboard, you must use a 'Know' working power supply.

I've already posted the details for checking the motherboard.

Unfortunately, while you can make an informed diagnosis, sometimes computer troubleshooting, is diagnostics by substitution.

Bev.
                    

Nel.

Good luck.

Bev.

Hi I'm back :(

Just tried with a working power supply, the results are the same: nothing works (just the fixed ambar light and the noise of the fans working really slow) So that means the motherboard is dead? bad luck,  what are the chances of all be ok and after a shut down the motherboard goes dead:emotion-7: Is there any chance to know if the processor is ok, or if it was the processor the lights on the back worked? since even them don't work. I bought a power supply for nothing, mine was ok, in this way I go buy a full computer in pieces without putting this one working :emotion-10:

Regards

Nel