Someone I know is having either mobo problems and/or PSU problems. His stuff is ancient but nonetheless I am trying to help. He has bought a new mobo but to make sure that it is not the PSU that is causing the problems and rather than buying a new PSU unnecessarily he has scavenged a couple of old PSU's the only problem is they have the old 20 pin ATX connection the motherboard need the 24 pin ATX connection. It has been suggested that he uses one of these http://www.amazon.co.uk/StarTech-co...1_2?s=computers&ie=UTF8&qid=1358883001&sr=1-2 I must admit to not coming across these adapters before. So my question is are these thing OK to use and if you could explain simply how do the work?
I've run many a 24 pin board off a 20 pin PSU - it will plug in all the way to one side of the socket, leaving four a pin group unconnected. The 20 to 24pin adapters just double up a few connections to supply power across the 24 pins.
Just to clarify Dave he could use the 20 Pin connection from the older PSU without any problems? The extra 4 group would be empty? Looking at the mobo with the ATX connection at the bottom then the connector from the PSU would be fitted from the left. Is that correct?
It will only fit one way, Glenn, but iirc my old media pc mobo had the retention clip at the bottom and the plug sat to the left. I may have one of those 24pin adapters in the 'cupboard of many things', I can have a look tonight if you wish?
If the old board has the 20-pin for the main power connector and the ATX12V 4-pin for the extra CPU, then yes, it should work and yes, four pins in the 24-pin main power connector will be empty. 20-pin to the main connector, 4-pin to the 4-pin next to the CPU. As you can see on the wiring diagram, the additional 4-pins in the 24-pin connector just adds one +12V, +5V, +3.3V and GND.
Thanks but no need as the guy that's having the problems live in the south or France so Amazon will be simpler if he needs to get one. This is the mobo and as you can see no 4 pin 12v header. So does that make a difference?
Ignore that image as I am an idiot. That is the possibly faulty mobo. This is the mobo he has bought and that has a 4 pin. So he does not need the adapter yes or no? Well spotted by the way. Asrock.
No, 20->24-pin adapter is never needed. You only need a PSU which has the needed 20 or 24 pins for main connector and the extra 4-pin CPU power connector. The reason why i write this is that if he has a pre-2000 ATX power supply, then it doesn't have the 4-pin CPU power connector and thus cannot be used.
Why not bridge the green wire to any ground, then test from there? Takes the motherboard out of the equation and eliminates a lot of labor on your part. From there, you can test voltages (assuming it powers up at all) to see if the PSU is the problem.
