OT computer issue

[hubops]

My old tower computer is now failing to start up. When powered on - it starts all 3 fans ; begins to boot for about 3 or

4 seconds - then stops. < fans off - nothing > I cleaned out some dust, wiggled some connectors, checked the MB battery. It has beed totally reliable for 10 years, but in recent 2 years has seen only occasional use due to the laptop taking over. P4 2800 XPpro HP machine. No hardware or software changes recently to cause this. Any intelligent guesses about where I could start troubleshooting this ? Thanks. John T.

[gfretwell]

Can you get it into the BIOS setup? Does it power off there too? Is the CPU fan running? That is the one that will overheat the fastest. You might just have a bad power supply but if it will hold in the BIOS setup the power supply is probably OK.

[hubops]

All fans running for the 3 or 4 seconds that it tries to start.

3 or 4 seconds isn't nearly enough time to boot - even when it was brand new and empty. John T.

[hubops]

Thanks - any quick and dirty test for the power supply ? .. before I go scrounging the electronic re-cycle bins. John T.

[gfretwell]

I was just wondering if you got as far as the windows splash screen. After that, a lot of things start happening.

[bob_villain]

P/S can often test good (with a shop tested) and not work under load. They have them sometimes at Goodwill or the like. Spikes will cause them to fail prematurely, but they are a common failure component. And the hard drive.

[dadiOH]

1. power supply

1. hard drive

[FromTheRafters]

[e-mail] was thinking very hard :

Have you tried cycling it again after a failed start, and before the platters spin down? It gives them a head start spinning up which might get you past the point of failure where everything is drawing power at once. Sounds like a weak power supply, and even more so if this little trick works.

[hubops]

Tried that - no dice - and I think there is a capacitor keeping for a second or two after it quits. Also tried un-plugging hard drive power & data - same results on power on. John T.

[Taxed and Spent]

if you can, you might connect the hard drive to another computer as an external drive and see what happens.

[Scott Lurndal]

If it is the later, you should still be able to boot from a bootable CD, if you can get into the BIOS.

[hubops]

Makes me think 1. power supply because I un-plugged the hard drive power and data with the same results. John T.

[hubops]

Yep - if I had another tower computer I would have tried a swap for trouble-shooting. alas .. John T.

[gfretwell]

If you think the drive is tripping the power supply, unplug it.

[makolber]

hit the F9 or whatever the right key is to get into the BIOS setup

[Nil]

On 01 Aug 2016, [e-mail] wrote in alt.home.repair:

You can test the voltages in the connector's pin pairs with a multimeter. You will have to google for a diagram of what the pins are. The pin configurations are standard for a given type of power supply.

As was mentioned, the test isn't definitive - the PS could act differently under load.

Another possibility is that some of the capacitors on the mother board or other components have failed. You can sometimes recognize a bad cap when it swells up and sometimes leaks. They can often be replaced, though there may be other damage that's not visible.

[Wade Garrett]

After 10 years of loyal service, put it out to pasture or give it a proper burial.

Your computing needs are modest if they're met with a machine this old. You can get a new, more powerful laptop in the $200-$300 range.

Toss that 30 pound CRT monitor that's taking up half your desk along with your five pound 30 inch wide clicking mechanical keyboard with the coil cord too ;-)

[Mayayana]

It won't be the hard disk. If that failed you'd see a message that no boot device was found. But you never mentioned whether anything at all comes onscreen. BIOS messages? Too quick for that, maybe? That would seem to indicate something prior to BIOS. Is the CPU fan running? If that died it might shut itself off. The power supply fan? I wouldn't suspect the power supply itself.

[Mayayana]

| After 10 years of loyal service, put it out to pasture or give it a | proper burial. |

Easy to say, but what if he likes XP and doesn't want to be stuck with Win10? The symptoms do sound ominous, but I've repaired a number of XP boxes that are still in use.

[gfretwell]

You can test the PS without a load by unplugging all of the low voltage cables, jumper the green wire in the big plug to any black one and it will power up. That does not eliminate everything but it is a starting point. The system board may be detecting something wrong with the voltages and shutting it down too. Some supplies want some kind of load like a 100 ohm resistor on the 5v but most ATX and newer supplies work fine unloaded.