Dead PC Syndrome

[avromark]

I know I haven't been on for awhile but I've been busy with work. (Why can't I be a CM?!)

System is a name brand with a 250watt who knows what power supply (Not even Lite-on). Pentium D 820 Smithfield with 2 SATA drives. I was connecting a second Optical Drive (non SATA) and now the system won't power up. Switched power cords, checked outlet, tried other outlet/cord with known good, resat all connections. I accidental snapped one of the prongs holding the front facia of the computer off so it kind of doesn't fit 100%.

I'm suspecting one of the three: Bad Power Switch, Bad PSU, static electricity fried mobo.

I'm probably going to replace the PSU even if it isn't bad since I don't trust it. But what is the probability of each? If it is a fried mobo is it worth trying to resurrect this system or would replacing it be more cost economical? Am I over looking something obvious?

I'm hoping it's not something stupid like a mis connection.

[erick13]

What happens if you unplug the new drive that you added? Does it then power up? If so it sounds like the power supply is too weak to everything. Check out the capiciators on the motherboard. If any of them are bulging or have stuff coming out of them then it needs replacing. My guess is that your power supply is the problem.

[avromark]

Nothing, I tried running it with no drives connected just to get it to BIOS. I'm thinking power supply and hoping it is. It's a 250watt can't even pronounce company name. My other PC (AMD Athlon 64X2 4400+) at least has a lite-on. But i'm thinking of replacing both, I'm crossing my fingers it's not the motherboard. Motherboard seems fine visually. I actually place the 3rd SATA HD into the other system awhile ago.

This is my "secondary" system it's only a few months old (yes I know it's slow, but some of us aren't quite as power mad as Monorail Man or Sir Clinky :P

I'm hoping I'll have more time and can view the boards once a week or so again.

Isn't technology grand?

[flynnibus]

Does the system get power? LEDs on the board... Fans turning?

Does the system POST or make any sounds?

If you get fans spinning, I'd unplug all the accessories, and leave just video card, RAM and keyboard attached. Then try to get it to POST. You might just have dislodged a connection like RAM which would cause wierd behaviors. But you haven't told us if the system even shows signs of getting power.

You could have simply knocked off, or reinstalled wrong, the 2 pin power switch to the motherboard.

[avromark]

This mobo doesn't have a LED light on it (very frustrating!), no fans whirring no anything, doesn't even get to POST beep. Nothing happens. This is an Acer so would the 2-pin power switch perhaps be part of a larger pin block? I'll check that again, I believe it's the one by the SATA plugs. Does the order you plug in the SATA hard drives into the onboard controller matter? I'm pretty sure I have them in the right order.

<- feels like he's about to get an ID #Ten T error

[flynnibus]

Originally Posted by avromark

This mobo doesn't have a LED light on it (very frustrating!), no fans whirring no anything, doesn't even get to POST beep. Nothing happens. This is an Acer so would the 2-pin power switch perhaps be part of a larger pin block? I'll check that again, I believe it's the one by the SATA plugs. Does the order you plug in the SATA hard drives into the onboard controller matter? I'm pretty sure I have them in the right order.

<- feels like he's about to get an ID #Ten T error

No, the power switch is the small individual connectors that go from the switch on the case, to header pins on the motherboard itself. There is usually a group of these wires/pins to plug in the power LED, Hard Drive Activity light, speaker, and power switch all together. Simply look for the wiring coming from the power switch and follow it back to your motherboard.

If you have no power at all.. start simple. Unplug the drives and any accessories you can from the motherboard, only plug in the power supply to the board, the case wiring to the motherboard, RAM and video card. If you don't get power, you either have a bad power switch, bad connections for the power switch, or your power supply is dead. Fried motherboard would probably still allow the power supply to turn on.

[Bruce Bergman]

If you don't get any lights or fans, or to the first step of Power On Self Test beeps, it sounds like fried power supply to me, too.

The only way to know for sure would be to get in there with a good voltmeter and trace out the low-level power lines from the power supply to the power switch on the case.

NOTE: Most PC supplies HAVE to have a minimum load attached to start - if you unplug the mobo it shouldn't start. They make power supply test rigs, and they have big resistors to provide that load, and probe points to check the voltages, plus "good power" lights for each output. BUT, they cost as much as a power supply does. If you only need it once it's not worth it.

If you haven't tried anything yet, look at the prices of both bare power suplies and new cases with a power supply installed - sometimes you can get a nicer case with a name-brand high output power supply already installed for less than an oddball power supply alone.

If that doesn't do it, go get a new Mobo and swap over all your hard and optical drives to the new case. It's not that your old one is confirmed bad, it's that they simply aren't worth the effort to ressurect.

There are only two kinds of computer processors: Prototype, and Obsolete. Moore's Law is moving so fast (transistor count and processor power doubling every 18 months) that by the time they get it into production and on the store shelf it's already ancient.

Says the guy who could open a decent Computer Museum from my personal 'elephant graveyard'.

--<< Bruce >>--

[avromark]

Thanks for the advice everyone, been busy with overtime. I'm probably going to get a new case/power supply on my next day off. I love how computers are commodity pricing now. Now the question of course is which case should I buy? I'll be like a kid in a candy store.

I haven't built a PC in awhile been buying assembled. I'm thinking I added to much for what the 250watt could handle. At least it wasn't my main PC. I have a closet full of obsolete systems Too think of the days when we thought the difference between a P5 60Mhz and a P5 66Mhz was huge. The last PC I fried was a PII 400Mhz, so I'm guessing I haven't done too badly.

I'm 99% sure it's either the power supply or switch, since I think I snagged the wire. No big loss Acer cases aren't exactly things of beauty.