Hard Drive

[denise66]

Hi, Don't ask me technical terms, cause i don't know them  , But i was wondering what would cause a computer not to start when you plug the hard drive power plug in, take the power plug out and the computer will start

[Dusty]

Welcome to the CH forums.

You state

take the power plug out and the computer will start

but what do you mean by start?  Will the pc start Windows or just apply power to various components?  Is the drive you mention a second drive you are installing or the one and only hard drive in the pc?  If the latter, Windows will not start without the drive being connected to the power supply, if the former then then one or both hard drives may not be jumpered correctly if they are parallel ATA (pata) drives (serial ATA {sata} drives do not require jumpers).  The problem could also be generated by a defective power supply unit.

Hard to advise you further without more details of what, if any, problems you have encountered and why you began unplugging/plugging a component in the first instance.  Some specifications of your machine, especially the manufacturer and type of your hard drive(s), would be appreciated.

[denise66]

Hi, The computer was given  to my son and it had no hard drive in it at all. I think i must have done something to it, cause originally it ( the harddrive) worked,  But before this little drama happened, my son tried to add more ram, and then the problem just sort of esculated from there. The monitor wouldn't work, so we then tried a different video card, still nothing, then it started beeping which i put down to a faulty ram. and now the computer won't start, like nothing at all, the processor fan starts to turn then stops. But if you put a smaller hard drive in it, it will start up. I wouldn't have a clue as to what sort of computer it is ( no labels or logo's anywhere on it that i can see, but the harddrive is Seagate 80 gig. Sorry i can't be more help

[Geek-9pm]

Hard to say. Older computers may fail because of the build up of dust inside the machine. Related to this is oxidation of the connectors for the hard drive and the RAM chips.
Ofter overlooked  is the build of of dust inside the power supply. This can contribute to random 'shut down' of the power supply.
In your case, it would seem that one hard drive is sucking too much power, but that is rather strange. Hard drives do not take a lot of power. Unless the spindle is binding.

[denise66]

Ok thankyou, so do you think it's the hard drive or the computer, as i said if i unplug the power from the harddrive the computer will start. I don't know exactly what it does as we still haven't got the monitor working to find out.

[dlx]

do you have any idea about what year the computer was built?  i think your computer is a little old and the power supply can not provide energy to power the hard drive and the other components in the computer.

[Salmon Trout]

Sounds like the bigger hard drive may be faulty and is (as Geek said) may be dragging down a 12v or 5v rail. The fact that a using a different drive allows the computer to start tends to reinforce this conclusion.

[denise66]

Ok, so why would it have worked originally, if not enough power to start, unfortunaely i think it might be the hard drive as well...not that i would know, only because it did work and now it doesn't.

[Salmon Trout]

Ok, so why would it have worked originally, if not enough power to start, unfortunaely i think it might be the hard drive as well...not that i would know, only because it did work and now it doesn't.

Many people have this idea about hard drives that "If it worked yesterday, it must work today". Hard drives, unlike most electronic devices found in computers, are mechanical devices. That is, they have moving parts. Delicate, precision parts and a fast spinning set of platters on a precision made spindle in bearings. These can wear out, stick, bind, etc. Every hard drive ever made will, if not replaced, fail sooner or later. Sometimes this happens quite suddenly. You say the computer had no hard drive when your son got it. So therefore it seems you put in a drive that you had lying around. You do not say how old this drive was, or how long it had been stored unused, under what conditions, etc. If a drive is stored a long time without being used, the spindle lubricant can dry up. Also improper storage can cause harm - storing a drive on its side can cause lube to pool on one side of the spindle and leave the other side dry. When you start up this long-time-asleep drive, everything can seem OK the first few times then the bearing fails, the motor jams and it drains a lot of power in its stalled state.

[denise66]

Hi, No it was a brand new harddrive, although i had it for  a while, it hadn't been taken out of it's packaging.  Just curious, would a faulty ram cause any of this to happen.

[Salmon Trout]

Any number of things could cause this to happen. We don't know very much about this old computer that was passed down to your son... how old it was, for example. Possibly there was a reason why the previous owner was willing to part with it?

[denise66]

Yeah your right and unfortunately i can't tell you to much either, but i can probably find out roughly how old it is , it belonged to my son in law.

[denise66]

Hey there is a sticker on the processor, doesn't actually tell you what size it is, but has numbers on it, so would that or mabey ( it's an Intel processor i know that much ) the number on the motherboard give anyone any idea of how old this computer is

[Salmon Trout]

very likely one or other of those numbers will give a hint as to when the computer was manufactured. I only wondered because you might not, if you knew the computer was an old one, feel like spending a lot of money on it.

A though has occurred to me. You will appreciate that switching on a computer is not as simple a matter as turning on a light. In the first --small-- fraction of a second, a lot of things are going on. The BIOS, which is software contained in a chip on the motherboard, is attempting to get the computer hardware up and running and ready to start the operating system (e.g. Windows). It will test the RAM and also try to start up the processor. If these have a good steady voltage within specifications then the next thing is to check out the rest of the hardware.

A power hungry hard drive can take a big surge of power as it spins up to speed and drag down voltages so that the processor, for example, does not send the "OK" signal that permits the rest of the startup. As a result the computer shuts down. This can happen if a computer has a lot of drives attached. For this reason there is often an option in the BIOS called "hard drive delay" which delays spinning up the hard drive for a selectable time, usually from 1 second up to 5 or 10 seconds. This ensures that the processor has a good stable voltage when it starts. A borderline power supply (i.e. one that was only just powerful enough to reliably supply the computer before, and which is furthermore getting old) could well be another factor.

So maybe that explains the fact that a new and presumably good hard drive shuts the PC down while an older smaller one lets it start.

[denise66]

Hi Thankyou, yeah i'm not sure if i do want to spend money on it, it was just a spot of luck that i had that hard drive.  So if the power supply needs replacing and the ram neds replacing it will end up being a very expensive computer.  I was probably more curious a to why it would  do what it was doing, cause if i could fix it cheaply then i probably would, but it's not really sounding like a cheap problem,  I like to think i'm a computer wizz, but i'm soooo not. haha ( although i have managed to get a few old computers up and running again. Oh well, might have to give it up as a bad joke. But i do appreciate everybody's help and advice. If i do decide to keep mucking with it , i will let you know how i got on. Once again. THANKYOU