Intermittent power supply to hard drive

right im running vista 64 and the power supply packed up so i installed one i had from another pc as far as i no its ok but sometimes the hard drive fails on boot if u turn off and on by power button on pc it might pick up the hard drive 2 times out of the 5 and load makeing me think its the power supply checked hard drive all cables are fine checked lots of times but im thinking its the feed from power supply that runs to hard drive.?

It could be that the PSU is not powerful enough to power the PC - resulting in low voltages on the +12V and +5V lines.

the one in it before was a 450 watt im sure this one is a 550 watt power supply or dont that mean alot.

It depends on the manufacturer. Check the amp rating on each of the voltages (should be a sticker on the side of the PSU) and compare between the old one and the new one.

Failing that go to this link and calculate what you should be using.

Not all PSUs are created equal. Noname brands generally do not hold up over time. I rate Antec in particular for PSUs.

i will check let u now tomorrow thanku

I agree 100% with Nick.C not all PS are created equal a no name PS with a 550 watt rating might not be
putting out as much as a brand name 250 to 300 watt PS would. OK one thing for you to check if you are
using the 4 pin connector is the wires in the 4 pin molex connector if one is loose it will cause the problem
you are describing. I had someone bring their system to me for repair that was doing the exact same thing
the hdd would show up sometimes and not show up sometimes or it would freeze the system with no hdd
activity at all and had to be hard rebooted. I checked the 4 pin connector and it had a loose wire changed it
over to another 4 pin connector and it was fine afterwords no more problems. If you are using a SATA plug in
then try a different one and see what happens might just be a loose connection.

checked 24pin plug made sure it all was connecting all i can do with that at the moment without replaceing power supply i did look at power supply
dc out max +3.3v/+5v/+12v/-5v/-12v/+5vsb

ac input 230vac 10a 50/60hz.
en60950 (pfc)

[QUOTE=fred54321;2446209]checked 24pin plug made sure it all was connecting all i can do with that at the moment without replaceing power supply i did look at power supply
dc out max +3.3v/+5v/+12v/-5v/-12v/+5vsb

ac input 230vac 10a 50/60hz.
en60950 (pfc)[/QUOTE]

Is en60950 the brand? From just reading your problem it sounds like the PS isn’t working properly anymore. How old is that PS and do you have a name for the PS?? As the other two poster says not all are created equal. Most people forget that a good quality PS will be the hard of your PC performance but most forget that one single important part of the computer when fixing or upgrading their desktop system. Considering PS is the heart of the computer you should invest more into it just as one would invest in a high performance GPU. Those numbers you gave don’t mean much if the PS is a low quality as they test in control environment not under stress testing til it fails to know it’s limits also they probably don’t connect all the connections to know how it strains the PS as well. So in the end my advice if problems still persist get a quality PS cause all those power problem causing to the HDD will down the line cause you problems with the HDD and your motherboard and any other hardware requiring power on demand.

i can load vista leave it on desktop when i come back its on black screen
pci listings
vertifying dmi pool data
disk boot failure insert system disc and press enter.
its as if the power to hard drive as dropped of.
im useing a sempron processer 3000+ 1.61 ghz and running one hard drive and a dvd/cd rom

ac input 230vac 10a 50/60hz.
en60950 (pfc)

What country are you in? If the USA, that’s the wrong voltage for input.

i am in the uk

this one got u all stuck lol??

getit29 suggested that you try a different molex to power the HDD. Have you tried that yet?

i will be trying that today

tryd new molex sata power supply cable to hdd still the same problem

Have you tried changing the data cable to the drive, or just checking that it is well connected at each end.

(I once found that the cable had worked its way out of an IDE socket for no apparent reason)

checked ide cables both ends loads of times so not that unless i buy new one and see what happens

Can you try the drive in another PC?

yes i tested harddrive with seatools in my pc all ok when i try in this pc sometimes it finds the drive sometimes it dont i ordered a couple of new sata data cables just to rule out if there is fault and i will get back to u all.

replaced with new power supply still same problem when i reboot search ide no harddrive found