The Mother Board

[fm47]

Could you go more indepth into that? If the power supply was having problems, wouldn't it stop working all together, instead of working some times but not others? Or is it supplying the incorrect amount of power?

[pbailey]

No!

I have seen a few times it will stop giving power to CD and/or Floppy!

Most of the time they will just go all at once.
_________________
The day you stop learning, is the day you die!

Paul

[Karlsweldt]

A power supply or PSU works the hardest of any component. It depends on a constant stream of cooling air. Air is loaded with dust and debris.. which will attach to any component in the case, including the fan's blades. A once-yearly cleanout is recommended. But be very cautious about opening a PSU case.. there are dangerous voltages present inside!! If the unit is left unconnected to the mains for more than 4 hours, it should be completely safe. But a few attempts to start a mobo with no mains cord should also be sufficient. Where the mains power enters, those large capacitors and heat sinks are the items to be wary of.
The fan in a PSU is normally mounted by four large screws.. easy enough to dismount and service, if need be. It is the brushless design, identical to what is used on the CPU's HS and video cards. Friction is its worst enemy. The blades can be nudged with a toothpick, and if they jiggle to a stop, all is well. But if they coast to a dead stop, the fan's bearing is dry on lube. Easy enough to relube any fan.. peel the back label, there may be a small rubber plug covering the bearing. One or two drops of light machine oil (3-in-1 or sewing machine oil, even ATF) worked into the bearing by finger-spinning the blades for a minute will suffice. Blot out the excess with a tissue, and remount for more years of service.

No homeowner or tinkerer should be without a digital multimeter. Very handy for almost any check of voltages or circuitry. Very easy to check those PSU output mains with it. Any black lead terminal is the common.. and the color of the wire indicates its voltage/use.
Refer to the diagram below.. of a 24-pin ATX power plug. The 20-pin plug is identical, less the bottom four leads. Ideally, all voltage readings should be within +/- 2% of rating or 1%, ideally. Don't be too concerned about the -12 volt reading.. it is only a reference voltage, and can be off by 5% and still be good. The -5 volt source may not be present.. not normally found on modern setups.



The one lead marked as "PSGOOD" or "PG" will present a +5 volt signal only after the PSU has stabilized from the start-up load. This signals a tiny chipset to enable all the mobo circuits to become active. If the level is too low, then no action.. although the chipsets become warm, and fans may spin. The lead marked as "PSON" will show about +5 volts only when the PSU is not active.. and near zero when active.

The POST process does a "head-count" of all features present, against a listing of what the BIOS pages reflect. If any conflicts are found, they may constitute a critical error.. which halts the process.
The keyboard LEDs are a basic diagnostics tool. They will flash once or twice on powering up, and again about 5~7 seconds later, as the POST process does a check on it. If no second flash, then there was a critical error.. 'all stop'.

Sorry.. long posting!
Hope it was informative.
_________________
F@H.. to solve mankind's maladies.. in our lifetimes!

[fm47]

Hey, don't worry about long posting, I'm grateful for such information. Although, I don't know anything about a multimeter, but perhaps will get one later in time. Before I go out and buy one, however, what else can I test to see what's wrong?

[Karlsweldt]

You can get a decent multimeter at nearly any hardware store. Just ensure it is the digital kind, they are more forgiving about DC polarities.. and no guesswork about where the needle is on the dial. The loading of an analog meter may produce improper readings on sensitive circuits.. where a digital meter won't. Have seen some "pocket" meters in the $30.00 USD or less range. Simple to use. Better meters may go into the hundreds of dollars.. but have many more features.
They also are handy for finding out which of those series-string Xmas light lamps have burned out!

Whenever a computer acts up with no definitive signs of the problem root, then down-build the system to its basic components that should produce a screen image and BIOS access. That would be the CPU with its HS and fan, memory and a video card. Plus the keyboard. Any drive ribbons can be left disconnected. All other device cards should be removed, also. Just ensure that any power connectors on the mobo (and video card) have a lead set from the PSU.

One great tool to have is a POST diagnostics card. Some aren't expensive, others are. But they display a two-character code for each POST step. If a character set 'hangs', then reference the code in its manual as a place to begin sleuthing. They also normally have small LEDs on the card to denote proper power lead voltage, as well as the oscillator activity and BIOS activity.. plus a reset function indicator. Newer models have an extension display on a long ribbon.. for remote monitoring. There are over 100 common POST steps prior to the hand-over, or bootstrap, for the OS to continue the operation. And it is all too common for a data ribbon to work loose on a hard drive, and the POST finds a "dead body" with no ID. Long hang-up!
_________________
F@H.. to solve mankind's maladies.. in our lifetimes!

[fm47]

I'm using my cousin's computer, so I haven't read everything, but I'll post on what I did so far to test what's wrong.

I used a different PSU, of which I've comfirmed to work. I also tried a different video card, but nothing is different. I've only the essential things to run a computer attatched (audio card and ethernet card removed). I also tried a differen't ram, although I'm not exactly sure if the Pins match. At any rate, it seems to me that it's most likely that my motherboard is dead....

I found no bulging or burn or crack on my motherboard... front and back. What do you guys make of this?

Excuse me for the slow replies, I do not get many chances on checking this ><

[Karlsweldt]

Not to be repetitive, but when obvious signs don't point to a failure cause with a mobo, then testing the CPU in a system that can use it to ensure it is good.. same with memory.. and then testing a known-good CPU and memory that is compatible to that troubled mobo will proof out whether the verdict is indeed "DOA" for it. Of course, a known-good PSU would need to provide its power.
And stripping down the build to where the mobo is placed on a non-conductive surface outside the case, with the PSU.. and a minimal build to effect a go/no-go condition. Most failures result from over-voltage sources or shorts.. or excessive temperatures. And the brutal surge of lightning! But some components do fail of their own course over time, and only expensive diagnostics equipment can reveal the cause.. but is it worthwhile?

This is not advised to do except by experienced techs.. but when a mobo fails to exhibit signs of life, set it up in a minimal build status.. with known-good components. Use a 47-ohm 1 watt resistor to bridge between the +5 volt source and the PG signal wire, after at least 10 seconds of the PSU being active. If the mobo comes to life, there is a problem in the circuit that monitors the reference voltage.. and not much can be cost-effectively done to correct the problem. If no signs of life still exist, then likely the BIOS has failed, or the primary oscillator has failed.. again, not much can be done. The mobo is a candidate for salvage rituals.
_________________
F@H.. to solve mankind's maladies.. in our lifetimes!

[billbird2111]

[evasive]

Hi Bill, thank you for the non-technical update on your situation and congrats on getting things together.

2007 was the year I got out of my previous (bad) marriage, right now I am happily married again, started my own thing as an IT consultant and getting things together too.
_________________
We hate rut, but we fear change.



System error, strike any user to continue...

[billbird2111]

I like your signature. We fear change but change can often be the best thing to happen for you. Change presents new opportunities where there were once none.

Yes, I'm pleased to report that I still know Jack Squat about the inner workings of a computer, and I know even less about flash drives and things such as this.

But I do understand not to ever click on links that promise nekked young ladies or those messages that proclaim "ya gotta see this!"

I also grow a mean crop of heirloom tomatoes, which are useful in heirloom tomato martinis.

Bill