External Hard Drive power supply

[whitehotdawn]

My Seagate 750gb external Hard Drive (HD) did not power up two weeks ago. I called tech support and we determined that a the power supply (PS) is most likely the candidate.** The warranty apparently does not cover power supplies so I ordered a new one for $20. I was told the new PS should arrive in 3 days. After about a week without the receiving the PS in the mail I called up Seagate. I was told the PS was not in stock and that I would have to wait for an unknown amount of time before the PS could even be sent.

I've tried to find a suitable PS on the web, but I'm not sure what exactly I need. I know that I need a PS with a 12V and 3.0A output, but I'm not sure about the connector.

My Current PS:
I.T.E. Power Supply
P/N: 3494966
P/N: 100356849
Model NO.: NU40-2120300-I1
Input: 100-240V~50/60Hz 1.2A
Output: 12V 3.0A
Approval no.: N19250

The External HD is a 750GB Seagate
Part No.: 9BJ648

The connector is a single hollow pin.

I would like to order a replacement to speed up this process. Would something like this work?

Thanks,

sean.



**The power supply's LED lights up and pulsates when plugged into the wall (and not into the HD). In addition to it's pulsating light it makes a faint "click" noise. When the HD is plugged in and the power button is pressed the HD makes a faint "click" noise (the light on the button does not light up and the HD does not spin).

 

[Zepper]

Is the output AC or DC volts? bgmicro.com has both DC output units and AC output units. Polarity is important too + can be either on the pin or the sleeve - very important to know which - usually there is a diagam that says which - it looks like a dot inside a C with a line going to the dot and/or the C marked with the polarity.

This might be it: http://www.bgmicro.com/index.a...=VIEWPROD&ProdID=12293

You can find similar at allelectronics.com, jameco.com, etc...

.bh.

 

[Modelworks]

The supply you have is probably a switched mode supply, just like those in your pc.
They tend to click or chatter when failed.

Its supposed to supply 12V at 3A so its more than likely a switched mode, transformer designs cost too much when they get above about the 1.5A range, so you probably won't find a regular wallwart type adapter that will work.

Its not a rule but most of the time the plugs like you describe (barrel connectors) are center positive.

I did a quick look at some of the surplus sites and found this.

Edit.

Just noticed something:
http://cgi.ebay.com/12V-DC-3-A...39859760QQcmdZViewItem

Has 7 available.

 

[Zepper]

The one at bgmicro is identical, but cheaper by a lot - get a power cord for 99 cents too.

,bh,

 

[Modelworks]

The one at bgmicro is cheaper and looks like it work fine.
The ebay link is to the same adapter you have already , and its listed as center positive, so that solves the polarity question.

 

[whitehotdawn]

Thanks for the help. What is the difference between 12V @ 3 amps and 12V @3.3 amps, and will it make a difference for this power supply? If it doesn't matter, I think I'll go with the one from bgmicro. Now I just need to cross my fingers and hope that the PS was really the problem.

peace,
sean.

 

[Modelworks]

The difference in the supplies is that the 3.3 amp one has more power in "reserve" should it need it.

The 3.3amp supply will only draw that if it needs too, so if you hook it up to something that requires 3 amps, then thats all it will supply.

 

[Zepper]

+/-10% is within most PSU's tolerance range - IOW, technically no difference. And if there really is a parts difference to justify the extra 10%, then you just have a little extra if the drive ever needs it. I hear those large drives can be pretty power-thirsty.

.bh.