Computer Hope

Hardware => Hardware => Topic started by: bradfisc on September 24, 2005, 06:35:17 PM

Title: Erratic Behavior
Post by: bradfisc on September 24, 2005, 06:35:17 PM
I'd appreciate any help that anyone can provide:

The problem started slowly, and gradually got worse.

When I turn my computer on, it doesn't seem to do anything - the hard drive and CD lights come on, the fans come on, but the startup process doesn't seem to happen.  Then, after 5 - 20 minutes (if I'm lucky), it may begin the startup process (ie. the Windows XP loading screen).  However, the keyboard may or may not work, and if it does, it may only work for a while.

I've tried new keyboards, mice, and monitors to rule them out (everything else like printers unplugged).  I've tried it in different outlets also to rule that out.  My laptop computer hooked up to my keyboard and monitor works in the same outlet.

I took the computer in for repair, and they found nothing since it worked perfectly fine for them.

So I took it to a friends house, where it didn't work at first, then did after a while.

Still didn't work at home.

Took it to another computer repair place, where it worked fine.

Does anyone have any ideas???????  Someone suggested the power supply ... but why would the computer only not work at my house and occasionally at my friends?

(Pentium IV, 1.8 Ghz, 512 MB RAM, Win XP)

Thanks in advance.
Title: Re: Erratic Behavior
Post by: GX1_Man on September 24, 2005, 06:44:48 PM
Sounds like gremlins.

Do you have anything to risk by a reformat? Something to think about.

So it works fine everywhere else, but not at your house. And that is ALWAYS the case or it is intermittent even at your house?
Title: Re: Erratic Behavior
Post by: Fed on September 24, 2005, 06:53:58 PM
The supply voltage at your house may well be different to that at the computer shop or your friend's house.

You PSU (Power Supply Unit inside computer) could be 'on the edge' which would magnify any mains problems.

How does it start in safe mode?
Title: Re: Erratic Behavior
Post by: bradfisc on September 24, 2005, 07:22:38 PM
Thanks ...

I'd definitely prefer not to re-image.

If the voltage is different in my house, would a new power supply unit get my computer working again?

I can't usually get my computer to even come on, let alone try to start it in safe mode ... it's like the computer doesn't want to begin the startup process
Title: Re: Erratic Behavior
Post by: Fed on September 24, 2005, 07:25:52 PM
Can you 'swap' your power supply just as a test?
Title: Re: Erratic Behavior
Post by: bradfisc on September 24, 2005, 08:27:38 PM
Probably not ... It would have to be replace it and take my chance, or try something else
Title: Re: Erratic Behavior
Post by: Fed on September 24, 2005, 08:38:09 PM
From what you have said, the only possible causes can be your mains supply, your PSU or a combination of both.
Can you run your computer off a different power point using an extension lead, maybe even from your neighbours house?

A quick question?
Aside from the location was there anything different when you tried it?
Mouse, Keyboard, Monitor?
Title: Re: Erratic Behavior
Post by: Raptor on September 25, 2005, 05:01:32 AM
Quote
I took the computer in for repair, and they found nothing since it worked perfectly fine for them.


Are there any diskettes or DVDs/CDs present?

Have you tried another power cable? What exactly has the shop used to test the PC that you haven't?
Title: Re: Erratic Behavior
Post by: 2k_dummy on September 25, 2005, 06:02:57 AM
Try running from a UPS. You really should have one.
Title: Re: Erratic Behavior
Post by: Raptor on September 25, 2005, 09:48:58 AM
Quote
Try running from a UPS. You really should have one.


If everyone would buy an UPS, Greenpeace would go mental.
Title: Re: Erratic Behavior
Post by: bradfisc on September 25, 2005, 10:53:59 AM
thanks ...

I'm not all that confident in what the computer repair places did ... they claimed that they ran a piece of software that does diagnostics, and it found nothing.

I'm not using a UPS, but I guess I could buy one and try it.

I'm living in the country, so it would be very difficult to run an extension cord from a neighbours house.
Title: Re: Erratic Behavior
Post by: bradfisc on September 25, 2005, 10:55:08 AM
By the way, there are no disk / CD's in the drive, and I have tried a new power cable
Title: Re: Erratic Behavior
Post by: Raptor on September 25, 2005, 11:11:48 AM
Have you tried resetting the CMOS?

Are there any USB hubs connected to your computer?

Quote
I'm not all that confident in what the computer repair places did ... they claimed that they ran a piece of software that does diagnostics, and it found nothing.


How much did you pay?

Title: Re: Erratic Behavior
Post by: Computer_Commando on September 25, 2005, 11:12:18 AM
Quote
...I'm living in the country, so it would be very difficult to run an extension cord from a neighbours house.

Measure your house voltage.  Maybe a bad transformer in your neighborhood.
Title: Re: Erratic Behavior
Post by: GX1_Man on September 25, 2005, 05:11:24 PM
Put a coathanger in the wall outlet while standing in water...NO WAIT - just kidding :o :o :o :o :o :o

The above answer about either the computer power supply or your house 's power seem to be the only logical explanations.
Title: Re: Erratic Behavior
Post by: merlin_2 on September 25, 2005, 05:19:49 PM
scan for bugs........run a diagnostic check...........on the hard drive......
Title: Re: Erratic Behavior
Post by: bradfisc on September 25, 2005, 07:08:05 PM
A couple questions...

- how do I reset the CMOS?

- How do I measure the house voltage?

And by the way, the cost was about $40 (give or take) at each of the places I took it.

Thanks in advance.
Title: Re: Erratic Behavior
Post by: bradfisc on September 30, 2005, 06:11:52 PM
Hi

I replaced the PSU, and still the same problem.

How could the voltage of my house do this?  Ie. everything else in the house works fine, and this problem seemed to get worse as time went on.
Title: Re: Erratic Behavior
Post by: Fed on September 30, 2005, 06:51:03 PM
You can measure the house voltage with a voltmeter.
With the powerpoint turned off...
Unplug the the computer plug from the wall.
Put in a double adaptor.
Plug the computer plug back in.
Make sure you have the voltmeter set to the correct scale and push the probes into the spare side of the double adaptor.
Turn on the powerpoint at the wall.
Check the voltage & compare the reading with what it should be for your area.
Then turn on your computer & watch for voltage fluctuations on the meter.
(All of the above terms may be slightly different for you because of your local language)

Just a note, if your supply voltage is supposed to be 115 Volts but you are only getting 100 Volts, your lights will still work, your toaster will still work, but your computer might not.