Power issues???

[rck214]

This is what happened, sorry if long, during an electrical storm this summer, I went to unplug all our devices that would be sensitive to electricity and the tower computer did not shut down all the way and I unplugged it anyway, for fear of frying it....well, it has not turned back on since.  I took it to a local place and they said it was not the power supply and had no suggestions, $100 later......
I got inquisitive and took the computer power supply out myself, checked to see if I could see anything specific that may be burnt or whatever,  and I saw nothing, put the power supply back in the computer and it worked~! for 1 week, but is now dead again.......
A green light on the motherboard is the only thing that lights up, sb power1 is what is printed by it, I guess that is standby power?

If anyone knows or has any other tests I could do or ideas, it would be greatly appreciated!
Thank you for your time.

[neelchauhan]

A Dell Dimension 2350 I got did something similar.
I tested it's power supply with another system "My Open PC" and the green light was the only thing on. I gone back to the old Power Supply and it worked.
I guess you can spend $20 on a Power Supply unless your PC is old, otherwise, get a new or refurbished PC.

[patio]

Why you would ever suggest a $20.00 PSU i can't fathom...

[rck214]

what is wrong with a 20 power supply?

[patio]

Only you can decide that...if you have a machine that has Hundreds of dollars of expensive components in it which all rely on steady durable power and you decide to just shell out 20 Bucks on it by all means...go for it.

[Geek-9pm]

Dell Dimension 2350 .
The above computer does not deserve a $20 power supply.
You can get a used one with everything for under $50.
As to the original post, in case of electrical storm is the computer was connected in any way to any kind of outside wiring the electrical storm would've wipe out the motherboard. This would be a telephone connection to the modem. Or if he had a DSL connection that also would wipe out the motherboard. In fact any kind of wire that came close to any kind of wire or metallic object that was exposed to the outdoors good channel a strong electrical charge into the computer. It wouldn't even have to do physical damage. I mean to say there's a no visible  physical damage. In some cases you may only see just a slight char or burn on a motherboard contact and that was it!
That is my best guess, using the information available. And yes, this has happened to me. In some cases it only burns out the device that was connected to the outdoors. For example if you had a modem, the modem would have been blown, but the motherboard survive. But it depends. Ideally, the telephone connection is supposed to have some  type of lightning protection built into it. But you cannot depend upon it.
A new motherboard for that model goes for about $150. I would sure not pay that much money for a motherboard for a machine that old. Instead, you could buy a refurbished model that had everything in it and would have some kind of warranty. That way you would have a source of parts for future repairs. If you wanted to stick with that machine for some sentimental reason. Anyway, I doubt very much that the power supply took the brunt of the electrical storm. Power supplies generally have good way of protecting themselves. But they cannot protect the motherboard from discharges coming in through other things. Things like that telephone wires or network wires or anything else hooked up to the computer other than the power plug. The poser [lug is grounded and has a suger protector inside the PSU. Or should have.

[rthompson80819]

Almost all phone lines have a lightning arrestor installed on the line, but they are not designed to be fast acting enough to save electronic equipment.

I believe the original intent was to keep a house from burning down rather than protect a motherboard.

You have got to have a very fast acting surge protector, or preferably a UPS, for every computer.

[rck214]

I just do not know what to do now.....as we initally spent about 1000 to have it built, but that was about 5 or so years ago.....I have a laptop for school, but would be nice to have the tower computer up also.

There was no connection to the outside during the storm, I have verizon for internet and it was not even on...as I stated before, I did unplug it as it was shutting down, then it would not start........I know enough to be dangerous!

Thank you all for your input!

So is 20 high or low for a power supply?

[Geek-9pm]

The replacement power supply for that computer is a 400 W power supply and cost about $20. It just may be that the power supply failed for no good reason. It may be that there was a buildup of dust and moisture inside the power supply and it failed. But the same could be said about the computer, a buildup of dust and dirt inside the computer could also stop it from working. A simple thing to do is just to plug different things and see if you can get it to start up.
What I meant to say is unplugged about everything you could think of from the motherboard. But to put the front panel connector and the power supply connector back into the motherboard. Next then put the power cord back in and see if the computer will turn on. Remember, you have to hold the power button in for almost 4 seconds. Also, check to see if there is a auxiliary switch on the back of the power supply. This caused a lot of confusion. I never have been able to figure out which way is often on on those things. So I would go back and forth trying to observe a switch, then trying the front panel switch, then trying that's again.And so on. When it turns on you should see lights flash on the keyboard and possibly a light on the front panel of the computer. If the keyboard flashes, then it may mean that the motherboard is really okay and the problem is with some other component.
As you say, the computer was not hooked up to any external devices. So then that would rule out the possibility of electrical storm doing the damage. We shall just assume that it's a coincidence.
Sometimes just unplugging connectors and plugging them back in makes things work. A small amount of oxide can build upon the connectors inside a computer if it is been turned off for while. Just the action of removing the connector and putting it back in and making sure it's firmly seated may be enough to clean the oxide off the contacts. The oxide film is not usually visible to the eye. It should not be necessary to apply a solvent to the connectors, but if you wish to do so alcohol is a suitable solvent, but avoid applying it with a cotton swab. The cotton swab leaves fibers behind. The soft cloth is better.

[patio]

If there's an internal modem card in that machine remove it...and buy a better quality PSU...

[rck214]

Thank you all for your input!  I will check out these things and if I cannot get it figured out, then I will try a power supply.

thank you again and have a Merry Christmas!