Faulty PSU?

[cromwell134]

Hi guys.
Im new to all this but its a pretty interesting place.
However, i got a 8k5a2+ recently, with an XP2200 and various bits to go with it but had a problem when I switched on. The PSU (its a Jeantech 300w, do I need more?) made a very strange buzzing noise and then quit with a lot of smoke coming from the back! The fuse in the power cable also blew. I got the case & PSU replaced but am now worried about turning it back on in case its something stupid!! Ive done & it happens again. The only thing I can think of is that i may have plugged in the cables for the switch, LED's etc the wrong way round? is this possible or could it just be a faulty PSU?

[loop]

well it doesnt matter which way the switch plugs on it will work either way, if the LEDs are on the wrong way round they just wont light up. If you check your motherboard manual you should find a diagram showing you how to plug them on.
What you describe sounds like a faulty power supply or you have put your motherboard into the case incorrectly. Could you have possibly forgotten to use the stands that come with your case to lift the motherboard away from the tray? Or could you possibly have used too many stands so that one of them is digging into the back of the motherboard? But from what you describe I would guess the most likely cause is PSU failure. It sometimes happens.

[cromwell134]

Thanks Loop. I have the correct number of stands. Is it OK to plug in the PSU without anything connected, just to see that it starts OK. The old one still starts but shorts out immediately the switch is thrown. If it shorts with nothing connected, I would guess the unit is faulty?
Cheers

[loop]

yes plugging in the PSU and testing it with nothing plugged in is a good idea.
If you plug the new PSU into the mains and then look on the big connector that plugs into the motherboard there should be a green wire and several black, connect the green wire to one of the black ones and the fan on the PSU should start up, if it does this okay then the PSU would seem to be okay. Once you have done that just plug it into the motherboard with only your ram, cpu and vid card plugged in. Hopefully that should solve it. I will try to ifnd a link detailing the method of shorting the green wire and black wire of your PSU.

[loop]

http://www.virtual-hideout.net/guide...ds/index.shtml
That should tell you how to turn on the Power Supply without connecting it to the motherboard.

[cromwell134]

Thanks, I'll try it tonight.
Much appreciated.

[cloasters]

Welcome to AOA Forums, cromwell134!

Originally posted by cromwell134
Thanks Loop. I have the correct number of stands. Is it OK to plug in the PSU without anything connected, just to see that it starts OK. The old one still starts but shorts out immediately the switch is thrown. If it shorts with nothing connected, I would guess the unit is faulty?
Cheers

So sorry to be the bearer of bad news. The only safe thing to do is remove the the power supply and give it a Christian burial. Sniffle. Sometimes an Irish Wake is more fun. Or simply throw it into the bin with a "good riddance" for luck.

Is your machine AT or ATX form factor? If it's AT, the power supply will turn on when you press the button on the front of your case-- even if the PS isn't connected to the mainboard. An ATX PS needs a "power good" signal from the motherboard before it will turn on.

If the PS is connected to the motherboard with two plugs that are connected to the mobo's one power plug, side by side(the black wires of both plugs are close together)you have an AT machine. The plugs are often labeled "P8" and "P9" if memory serves.

If the power supply has one 20-conductor plug that connects to the mainboard's 20-Pin receptacle, it's an ATX mosheen.

ATX PS's can fire up if they are not connected to a mobo, but you need to fool the PS into "thinking" that it's connected to a mainboard.

If the LED's that are visible on the Front Panel of a case are connected to the little block of brass pins on the mobo backwards they simply don't light up. They don't smoke the machine. Here's an easy way to ascertain if the box is ATX: Is there a twisted pair of wires from the front of the case with one plug on them that's marked "Power?" This is inside the case, of course. If not, it's an AT rig.

Let's hope that your smoking PS didn't take the mainboard and the components that were on the mainboard with it. If so, you have my sympathy.

[cromwell134]

Thanks for the advice guys.
Plugged in a new PSU & just went for it - & came up smelling of roses!! All is now well &, funnily enough, much faster than my old PII 350
Cheers & Happy New Year to you all.....

[cloasters]

I love happy endings. Good on you, cromwell134!

[cromwell134]

Unfortunately all was running well, until I plugged in a new Floppy drive & CD Burner. Then nothing. Not even an attempt to boot up. the drives all fire up (the floppy light stays on!!), the processor fan spins & the fan in the PSU but not the fan in the case. the power and HD LEDs do not light up, except the HD light which flashes once then nothing. There are no POST codes, its as if there is power to only half the board, is that feasible?? Everything was fine, had XP running a treat, loaded a few driver updates,etc switched it off Monday night, then Tuesday night - nothing! have tried everything I can think of, removed the new drives, etc all with the same result! Damn thing!! Could 'part' of the PSU be at fault? I'm going to try and lay my hands on a 'spare'PSU & try it out.

[cromwell134]

Unfortunately all was running well, until I plugged in a new Floppy drive & CD Burner. Then nothing. Not even an attempt to boot up. the drives all fire up (the floppy light stays on!!), the processor fan spins & the fan in the PSU but not the fan in the case. the power and HD LEDs do not light up, except the HD light which flashes once then nothing. There are no POST codes, its as if there is power to only half the board, is that feasible?? Everything was fine, had XP running a treat, loaded a few driver updates,etc switched it off Monday night, then Tuesday night - nothing! have tried everything I can think of, removed the new drives, etc all with the same result! Damn thing!! Could 'part' of the PSU be at fault? I'm going to try and lay my hands on a 'spare'PSU & try it out.

[Uncle Bob]

It's possible that when your PSU fried, it fried because something else caused it to fail. Have you disconnected the drives and tried it again?

[cromwell134]

Yep, tried disconneting all drives, leaving just the CPU and RAM and AGP card in, still doesn't even try and boot! no signal from graphic adaptor to monitor, no beeps and no post codes - fans turning tho? dont know where to look unless its the PSU again?

[Uncle Bob]

Originally posted by loop
http://www.virtual-hideout.net/guide...ds/index.shtml
That should tell you how to turn on the Power Supply without connecting it to the motherboard.

Originally posted by cromwell134
Yep, tried disconneting all drives, leaving just the CPU and RAM and AGP card in, still doesn't even try and boot! no signal from graphic adaptor to monitor, no beeps and no post codes - fans turning tho? dont know where to look unless its the PSU again?

Did you try this again? What were your readings? It seems PSU's are hard to troubleshoot when connected to a board unless you can put a voltage probe down into the connecot. It's easier when disconnected from mobo.
Don't give up, we'll get to the bottom of this!

[cloasters]

cromwell134, how goes the battle with your reluctant machine?
I hazard a guess that the PS that took up smoking at a very early age also forced your mainboard to "get the addiction," too. Dayam, this is a nasty way to start the new year.

[cromwell134]

Well guys, the story continues.... New power supply was fine but still no response from the machine! exchanged the CPU (just in case) - still the same. Exchanged the MoBo and Bingo, we now have a machine that boots - for a while. Then get Hardware Malfunction - System Halted. Sometimes Win XP will start and sometimes it wont!! I have read about this problem recently, I think its misleading and nothing to do with Hardware failure at all and more likely a drivers problem. I think I will clean the hard drive and reinstall XP, although currently even the XP setup falls over!? Has anyone else any clues about this? Thanks

[Uncle Bob]

Originally posted by cromwell134
Well guys, the story continues.... New power supply was fine but still no response from the machine! exchanged the CPU (just in case) - still the same. Exchanged the MoBo and Bingo, we now have a machine that boots - for a while. Then get Hardware Malfunction - System Halted. Sometimes Win XP will start and sometimes it wont!! I have read about this problem recently, I think its misleading and nothing to do with Hardware failure at all and more likely a drivers problem. I think I will clean the hard drive and reinstall XP, although currently even the XP setup falls over!? Has anyone else any clues about this? Thanks

I assume you are running the same mobo (8K5A2+ ?) You may want to flash to latest BIOS: 5A2P2B01.BIN and install the latest 4-in-1 VIA drivers. If that doesn't work, you may have to do a fresh install afterall.

[cromwell134]

BIOS is flashed, 4-in-1 drivers are installed. Fixed the problem by disabling SSED?! Saw this in another post somewhere. If SSED enabled, I get a blue screen and lots of errors on the hard drive. With it disabled, the machine ran quite happily for hours, installing & upgrading stuff. What is SSED anyway, what are the advantages and is there a problem with this board and the XP2200+ in general? The first board I had didnt seem to have this problem, but then again it died after working fine for a few days!!