psu problem?

[Mr anderson]

hi me again, im having problems with a psu, the one im using is a p4 atx 250watt. now what happens is, when i turn the computer off, the fan on the psu keeps turning? now i thought it could be the psu, but i have another psu in my main system, so i tried that & it does the same? could there be a fault with the motherboard?


any help would be great, cause im lost on this

[redwudz]

I've never had that happen.

Do all your indicator lights and drives shut down when you turn off the computer or is it only the fan that is running?

AFAIK, there is only one sense lead in the PS ATX connector at the motherboard and this is what tells the PS to shutdown.

Many newer PS's keep some power on the RAM or motherboard after they shut down for use to 'waken' the computer from standby or hibernation, but the fan doesn't run.

Simple things first; Are you shutting down using Windows? Try shutting down using the front power switch. (Make sure the computer isn't doing anything important, first. ) I'm wondering if your front power switch is sticking. If you want to test it you can switch motherboard leads with the reset switch, they both work the same way.

Another possibility is that you have some power settings wrong and it's going to 'standby' or 'hibernate' mode and the display and drives are just off, but not the motherboard. You can check this in Control Panel>Power Options and set it to 'Always on' to disable these modes.

I'd suspect the front power switch or the Power Options settings before I would the motherboard, but anything is possible.

[Mr anderson]

the fan on the psu, yep using windows method on shuting the pc
down. havent tried the front yet ( but when i put the power cable in the psu, the fan start anyway, and the pc is not on)
ive just reformatted the pc, but will check the settings, will check the cables to.

[ROF]

Some motherboards are incapable of shutting off the PSU. This might be the issue here. Which Motherboard model or BIOS Model and Version is this machine?

[Mr anderson]

its a trigen motherboard imperial, emachines, 2.6 intel, using a atx p4 250watt psu.

[Mr anderson]

any iedas?

[Mr anderson]

hi ok its a emachines 820, using a intel p4 2.6, and pc2700, what mo bo, could i use for this?

[iLuvLandingStrips]

a new trigen motherboard imperial?

[redwudz]

If you are convinced the motherboard is bad, you first need to determine the size of it to replace it. It's likely a Micro ATX with a on-board video and audio. Emachines generally use economy MBs and parts.

Micro ATX form factor 24.5cm x 24.5cm ( W x L ) 9.6in x 9.6in ( W x L ) more or less for comparison.

You can go to one of the major online companies, NewEgg, Tiger Direct, Directron or others if you are in the US and see what they may have available for a P4 2.6 in your MB size. Also check that your case can accept a different MB. It should have a removable panel that the MB connectors pass through. Not all MBs have the same layout for connectors such as video, mouse, etc.

This may be more than you want to tackle, though.

[ROF]

The Trigen line of motherboards used in eMachines do not power down the PSU. You need to manually shut it off. The imperial line requires the use of a proprietary PSU. Notice the extra power connectors next to the 20 pin ATX Connector? You can only use imperial boards with this PSU.

[Mr anderson]

so, all i got to do is pick up a new psu (reason the fan has died in it) and there's nothing else to worry about with it?

[redwudz]

It looks like ROF is familiar with that computer. It also sounds like you would have to pick up a E-machines PSU and that may be the only one you can use with that MB and computer.

If all else fails, you can replace the PSU fan or have somebody do it for you. They are commonly a 80mm 12V box fan with 2 leads, no thermal diode. (Three lead connector)

But the leads may be soldered into the PSU circuit card. If you want to try this: Unplug the PSU and remove it from the computer. Let it set at least overnight or longer to discharge the capacitors and be very careful with shorting out any of the internal connections with metal screwdrivers and the like. Low voltage, but lots of amperage there.

Replace the fan, and either solder the new leads to the board or better splice them into the existing wires and tape them or use shrink tubing for insulation. If you are lucky, it may have a plug in connector.

Don't know anybody with an electronics background? Go to the local community college and find a electronics class. Bribe a student with a six pack of beer. (A legal age student ) When I was a electronics student, I would always work for beer.

[Mr anderson]

i can do the psu, np, just ive never seen this b4? whn u said about the psu, i used my other psu out of my own custom pc (atx 500watt ) or does need to be a eMachines psu if so where can i get one? thnx 4 the help :P :P

[redwudz]

If the other standard PS worked with no problems, then you should be OK with one similar to it. Probably a 300W would be more than enough for your setup. I forgot you mentioned earlier that you had tried a different PS.

I've only worked on one E-machine, so I don't know much about them. I know at least the low end models tend to cut corners on quality to keep the price low, but some members have newer ones that seem to perform well for them.

[Mr anderson]

great thnx all for ur help, uve been great 8) 8) 8)