Hi friends,
I bought a new ATX power supply for my PC and after connecting it the PC was not working properly.It will restart at random and at last it refused completely to boot up.When I checked the PSU ,it was found that there were no connction to the 18th pin (as learned from some sources,the -5 V DC ) of the unit.It was missing at time of manufacturing.My doubt: is this 18 th pin is not necessary for the PC to work? Could its absence damage my mother board?

Please help me....The quote is extracted from here..

"Some of the voltage lines on the connector may have smaller sense wires which ALLOW the power supply to sense what voltage is actually seen by the motherboard. These are pretty common on the 3.3 volt line in pin 11 but are sometimes used for other voltages too. The -5 volt line on pin 18 was made optional in ATX12V 1.3 (introduced in 2003) because -5 had been rarely used for years. Newer motherboards virtually never require -5 volts but many older motherboards do. Most newer power supplies don't provide -5 volts in which case the white wire is missing."

Good luck

without the information regarding the computer make and model and any or all components motherboard/cpu/ram/hard drives/ the operating system etc as well as the make model of the older psu and the make model of the replacement it makes it very difficult for any of us to give you any guidence on your problem and how to resolve it.Thanks a lot for attending my problem
My spec is
Intel D845 GVSR Mobo(AMI BIOS)
P IV 2.4 Ghz CPU
Hynix RAM DDR 333 256 MB x 2
Samsung 80 GB HDD
OS Win XP Pro

Old PSU was ATX 400W Intex
New PSU is ATX 400W frontech

I put it to a bare minimum with the Processor and One RAM only but no avail.If even the one RAM stick is also removed, it will beep 3 times.If the ram is reinstalled, no beep,and a black screen only.The CPU fan is working.I am not familiar with the frontech brand...
Not exactly a name that inspires confidence.
They are probably Far East manufactured PSU's labeled for sale overseas.
For a decent 400W psu you can expect to pay around 40 to 50 bucks but it is well worth it.
I've seen brand new Far East PSU's have problems out of the box and a few that were completely dead.

Consider this ...with the cost of all the components inside your PC the PSU is probably one of the most important parts...don't skimp on it when purchasing.http://www.newegg.com/Product/Product.aspx?Item=N82E16817170017

prove Patio wrong !!!!


lolBeen USING one of these for about 9 months and very pleased with it: http://www.newegg.com/Product/Product.aspx?Item=N82E16817104953

Much better user reviews (see newegg.com) than the one honvetops posted. Quote from: honvetops on September 01, 2007, 09:02:15 AM

http://www.newegg.com/Product/Product.aspx?Item=N82E16817170017

prove Patio wrong !!!!


lol