Need advice, HDD connection.

[#1]

Right, I have been given a computer base unit. I was told.... 'it was working when I switched it off, but when I switched it on....'
I have checked it at home, and found they had opened the unit and disconnected most of the cables and removed the Ram.
When I have reconnected the cables and Ram I get an error message ..' no signal, check data connection' on monitor.  So I confirm data cables not damaged by connecting my desktop pc. Then look at the faulty one.
When powered I get the hum and the hard drive vibrates - suggesting it is working. The motherboard has a green light. So power is reaching there. However I get no Bios screen, or cursor or signal to monitor.
I removed the graphics card, and tried again. No signal.
I was going to try connecting one of my other hard drives to see if that would get some response. But the connections are totally different.
My question is this... Should the hard drive have a data cable, separate to the power cable? My other hard drives have separate connections for power and data. I have enclosed a picture of the hard drive, removed from unit, with the only connection I have for it. I'm not sure if a cable is missing. it's a Samsung HD501LJ
.
I believed that even without a hard drive, the Pc should still boot to Bios if nothing else.  If this is the case then I will probably need a new motherboard. Any ideas anyone?

[#2]

There needs to be a sata cable to the hdd. Flat ribbon about 1/2" in width, fits on the connector next to the power.
Some mb's are iffy about having their hdd's removed. Try clearing the cmos usually a jumper next to the battery.

[#3]

Yes, HB is correct (of course), it's a '¬' shaped connection (similar to but smaller than the power one) and there will be an identically shaped connection on the motherboard.

[#4]

Great!!. many thanks. Will see if I can find one. Do you know if this would stop the boot up going to Bios though? I just get the 'No signal, check connection' message on monitor.

[#5]

Quote from: rogadodge

When I have reconnected the cables and Ram I get an error message ..' no signal, check data connection' on monitor....  So I confirm data cables not damaged by connecting my desktop pc. Then look at the faulty one. When powered I get the hum and the hard drive vibrates - suggesting it is working. The motherboard has a green light. So power is reaching there. However I get no Bios screen, or cursor or signal to monitor. I removed the graphics card, and tried again. No signal. . I believed that even without a hard drive, the Pc should still boot to Bios if nothing else.  If this is the case then I will probably need a new motherboard. Any ideas anyone?

True.
You don't need any hard drives.
Try holding the delete key (or similar) down when you boot to get into the BIOS.
Not all PC's display a picture etc whilst booting.
Hard drives shouldn't hum or vibrate (much) - but fans should.
I get the no signal message (briefly) when my PC powers off the graphics card, it's produced by the screen when you have power but no video signal present.
You could try the screen with a different PC.

[#6]

First i would ask , when you press the on button can you see the PSU fan running ?  Then do you hear some BEEPs this should tell you if everything is ok or not  , most common cause is the memory not seated correctly this would stop the POST

[#7]

I've just had an ASUS P5N-D that wouldn't POST. Turned out 1 of the pair of memory modules had died. Took me ages to figure out because the MB beep code didn't specify memory (I was also thrown because it was Ballistix tracer and all the LED's still worked)
Normally, motherboard speakers are really handy for fault finding.

[#8]

Quote from: rogadodge

I get an error message ..' no signal, check data connection' on monitor.

That means there is no detectable graphics output.

Quote from: rogadodge

However I get no Bios screen, or cursor or signal to monitor.

Because you have no graphics output.

Quote from: rogadodge

I removed the graphics card, and tried again. No signal.

I presume you mean you reseated the graphics card (i.e. put it back in again before you tried again).  That won't work if the card has failed and graphics cards are prone to failure.
You probably need a new graphics card - at the very least you need to try that before you do anything else.  Or put the graphics card in another computer to prove whether it works or not.
Some motherboards have an on-board graphics output.  Your computer will default to that if the graphics card fails so if you have one, plug the cable in there.
Yes, yes, it could be a POST failure before the sequence gets to the graphics output stage but I see at least 20 graphics card failures for every one POST issue that isn't cured by re-seating the memory.  Statistically, it's a failed graphics card.

[#9]

Just an idea - you said the RAM had been removed - is the CPU still there?
Richard.

[#10]

In my above post I said I couldn't get the MB to POST. What I ment was I was getting the same error as rogadodge 'no signal, check data connection'. The MB green light was on with CPU and graphics fans spinning away.

[#11]

Quote from: ID

... I said I couldn't get the MB to POST. What I ment was I was getting the same error as rogadodge 'no signal, check data connection'.

This means there is no output to the monitor.  So either the computer does not complete POST or it does but you never know it because the graphics output isn't working.

[#12]

The condition of this system is very suspect....
When you said the ram had been removed, do you mean there was no ram in the system and you fitted your own, or it was in the case but not in the ram slots?
As Rich has suggested earlier, have you checked that there is a CPU fitted... power off and unplug power cables, remove heatsink and see if there is a processor chip underneath.
No video signal can mean the mobo is dead, the processor is dead (or not fitted) or the graphics card is dead.
One thing to check... Remove all drives, cards, cables and memory so you just have the PSU, CPU (+ heatsink) connected. Then try powering it on... If the processor is working the system should beep several times to tell you there is no ram fitted.
If you hear nothing the system is no good.

[#13]

Thanks peter, et al...
                                   I have tried all the suggested remedies and come to the conclusion the motherboard is dud. maybe the cpu is dead as well, but definitely the motherboard. So I have removed processor, ram  graphics card and dvd r/rw for donor parts. scrapped case, power unit and most old leads. Now I can play at 'computer geek' and try and build my own, 'new' computer.     Keep me from under the me'm sahibs feet.

[#14]

could have been a shed of things ...
specially if its a older computer
i have a old sd-ram with AGP radeon i quit often i get the same problem you had
it could be any faulty component best way to try it is put 1 stick of ram a cpu +fan and a vid card (no hdd cd ect)