No Power after replacing HD

I replaced a hd in a dell precision 370 with a SATA . After putting in the drive, connecting the cables, and plugging it in, the computer will not power up. I know my power supply is good because I have the green light on the MB glowing. I tried with another computer and the same thing. Is there a step I'm missing in dropping in the hd's? Thanks for any help because I have about 20 of these computers I need to get up and running for student tutoring.

 

I don't know if they were SATA. But would the computer not power up at all f the drivers are not loaded? How would I load the drivers if I can't get the computer to turn on? Thanks again...

 

I really can not power up the computer. The greenlight turns on on the mb when I plug in the computer, but when I try to power up, nothing at all. So I get no where. That's why I wondered if I have to do something other than drop in the HDs and plug them in. I seem to be missing a step!

 

Did you accidentally flip the power switch on the back of the power supply to off?

 

I don't have the old HD. The company who gave us the computers pulled their HDs. That's why I have to replace them.

I looked to make sure the power was on 110 and not 220, but not sure there is a power switch on those computers. I just tried to press the power button on the front and I get nothing.

Thanks!

 

I am at meetings all day so I will check that tomorrow when I am back in my office. Thank you!!

 

A good check to see if the board is working is to see if it beeps at ya. Typically taking out the ram sticks would be a good check. Though, I wonder about the psu.

 

I took out the HD and no power to the computer that way either. We so need these computers for kids. Please tell me I'm not out of 10 computers!!!

 

I have 2 out of 10 computers in my office and neither of them has power. WOuld it be possible that all the psu are bad? As I say, I need these computers so badly!! Thanks for any help.

 

Hello,
Can you do the following.

Pull out the power cord from the computer.
Hold the front power button down for 30 seconds.
Connect the power cable and then try to boot.

 

Held the power button and still nothing. Thanks though...

 

I'm wondering whether these PC's have been 'spiked' somehow or whether you were unlucky picking up the two faulty ones.

You've tried using power connectors from a different cable set? There are usually several bunches of cables exiting the PSU, usually 2 or more will have hard drive connectors on them, it may not be the case if the PSU dates from early in the SATA introduction though.

Maybe some photo's from your cellphone or better would help us visualise what might be happening here?

 

On these computers there are 4 diagnostic lights, front on the desktop and rear on the tower. Are they lit? If they are, see here for codes.