My grandaughter has an Advent 3105 desktop.It was never any trouble until one day it just wouldn't start-no lights,no anything.I thought it might be the psu,after first checking the cable.When switched on the fan doesn't work,but the smaller case fan beside it comes on for a few seconds and a green light on the motherboard comes on and stays on untill switched off,when it goes out gradually.I assume this is some sort of residual current held somewhere else.I have looked into getting a replacement psu but on the cabling is a 6 pin
aux connector on the motherboard which none of the others appear to have.The cabling for it is 3 black,2 orange,1 red. I know i is not a PCI Express as that is 3x2,this is 6 in line.
Can anyone point me in the right direction,assuming it is this which is at fault.
Regards Rogerok

quick thing to do go get a power supply tester most of the time there around 15-20 bucks so nothing major.

that is the only way to find out if its the power supply or not

if you dont wanna pay the money to buy a tester take it to a computer technician and they should do it.

only takes a minute or so to find out if it is good or not but is great help to find if the psu is the problem or not

is this an older P4 computer if so it could be a plug for the P4 ,earlier ones had them i think ,before the switch to the square 4 pin one ,the problem sounds like the psu,its putting out a little power when turned on ,but not enough to boot the system, the residual power is held briefly in the power supply ,what make is the motherboard in the unit

Acejames,I now have a Voltmeter to back test it while connected and it's the psu at fault,so thanks for the advice.Roger

Caperjack,Yes,it's an older p4 and I agree
with your diagnosis.I am afraid I don't know the make of motherboard,there seems to be no indication on it and I have no manual.I have also found out that the connector is to provide extra power when under a greater load.Can I simply replace the psu with a standard one or shall I start from scratch-new motherboard/new pc???
Cheers Roger

new tower ,would be my way to go if i were in your shoes. look at these full tower or barebones ,just add your hdd and cdrom .great prices
http://stores.ebay.ca/LU-COMPUTERS-I...Q3amesstQQtZkm

Many thanks,looks like a trip to ebay.