Computer Won't detect my harddrive

[Blue]

Well, last week, my computer decided to give up and not boot up. I got flustered, sent it to the pc repair shop down the road. Got it back yesterday, and it doesn't boot up once again. So went back down, they take me to the back, I see it booting up and he said some wires had become loose and it should be fine.
Well, I get it back, and it's a bit flakey in detecting the harddrive. Managed to boot up to a beautiful blue screen saying unmountable boot volume. So, I go to google, run chkdsk /r for 4 odd hours and manage to boot up fine. By that time it's one in the morning and i want to go to bed.

Now, try and boot it up this morning and everything runs for a couple of seconds and then just cuts out. The only way to turn it on again, is to turn it off and on at the mains, then try and boot up again. Sometimes it boots up but doesn't detect the harddrive, and once it boot up, loaded up a little bit of my desktop, then blue screened.

Sooo arghhh. Any solutions? I'm thinking the wire from the mains to the computer is faulty.

tl:dr - Can't detect hard drive in bios, any solutions?

[paul4wolves]

Perhaps a dodgy hard drive??
Get a new one off ebay and try it, you can get them for about £10 nowadays for a small one.

[Blue]

It worked fine when I was at the shop. They rebooted it a couple of times, and it had no problems :S

[paul4wolves]

could have been the ride home in the car that has dislodged the cable again, have a look. I can't believe you paid money for someone to fix your computer, there are hundreds of tutorials on the internet so you can fix it yourself.

[Blue]

I panicked, I had tried anything I could think of.

[paul4wolves]

I meant add before, Try and clean the case out because dust can be a conductor meaning that it will short circut your computer so if you get rid of the dust then that might just sort you your problem.

[Blue]

Dust free. On the times it does decided to boot, the hard drive light that blinks on and off, is just a constant light. Not flickering at all.

[paul4wolves]

It could be a dodgey cable. Try changing the IDE cable or SATA which ever it is you have.

[Blue]

I swapped the 2 SATA cables going from my disk drive (I know that works) and my hard drive, still doesn't boot.

[paul4wolves]

nackered hard drive.