PSU and USB related problem. I think...

[notEworthy27]

Ok so here's my problem. I can't get my external USB-powered HDDs to be recognized by my system. When I connect USB devices which have its own power supply, it gets recognized. But whenever I use my Seagate GoFlex 1TB Ext. HDD. It either goes bonkers on reconnecting and/or the system says that the drive isn't formatted. But when I connect the drive to other PCs or laptops, its being recognized easily. So the next thing in mind is the PSU. Would it be possible that because the PSU isn't able to to supply the USB efficiently, hence can't powerup the external HDD. Or is there something else I havent taken into account? Here's my system specs by the way:

OS Windows 7 Ultimate 64bit

CPU Intel Core i7 950 @ 3.0ghz

RAM 12gb DDR3 Geil

Mobo MSI x58 - Pro-E

Graphics Card Nvidia GeForce GTX470

2 LCD monitors

Hard drives: 1 SSD system drive, 3 1 TB, 2 500GB

PSU Corsair 620W Modular

Silverstone Raven RV-02 Case.

 

[luciferano]

The PSU shouldn't cause such an issue AFAIK, but it might be possible. The motherboard or USB drivers might be the issue instead.

 

[notEworthy27]

I've updated the drivers already. Same problem, no difference...how do I monitor the USB voltages? Btw, is the PSU enough to power all the whole system I have setup already?

 

[luciferano]

Without looking deeper into it, I'd think that it'd be enough. I could check to be sure, but it should be enough. It might be faulty, but its rated power delivery should be fine and its brand and line are reputable enough to think that it should manage at its rating.

 

[notEworthy27]

Ok. How could you check? So how about the USB problem?

 

[luciferano]

Checking would be doing a Google search for a proper review of that PSU and looking at stability and power delivery tests.

I suppose that you could test the USB voltages with a voltage meter and checking the power pins of your USB ports with it.

 

[notEworthy27]

what voltage reading should I see?

 

[luciferano]

what voltage reading should I see?

I think that USB uses +5V. You could go to the USB wiki to find out for sure.

 

[knightdog56]

Which USB ports are you using, rear ports from motherboard or front ports from the case. I always use rear ports for hard drives and front case ports for USB jump drives or camera connections.

 

[notEworthy27]

I think that USB uses +5V. You could go to the USB wiki to find out for sure.

+5v Rail via SpeedFan is at 4.54V. Ok I'll check the USB port voltages. Might be a defective powerline.

 

[notEworthy27]

Which USB ports are you using, rear ports from motherboard or front ports from the case. I always use rear ports for hard drives and front case ports for USB jump drives or camera connections.

I use both front and rear. Same problem with any other USB port. Though, other devices work fine. I have a wacom tab, works fine. I have a Logitech wireless keyboard and mouse set, works fine. Powered HDD docks, they worked fine. It's only with self-powered USB external HDD that the problem comes up.

 

[knightdog56]

Can you check all the red (5volt) wires from your main 24-pin power supply connector to your motherbard while it is running. That 4.54volt on the 5volt rail is low. If you have

5 volts coming in and low voltage on usb it would most likey be a motherboard problem.

 

[notEworthy27]

Can you check all the red (5volt) wires from your main 24-pin power supply connector to your motherbard while it is running. That 4.54volt on the 5volt rail is low. If you have

5 volts coming in and low voltage on usb it would most likey be a motherboard problem.

Finally! A tangible answer. Will check in a while and update. Thank you!

 

[notEworthy27]

It seems that the power supply might be the culprit. From my last post, the +5v rail was at 4.54. But just now, from a cold start, the +5v rail is at 4.80-4.92v. From the specs of most PSU, there is a leeway of +/-5% of the actual voltage being supplied. So thats at 4.75v on the minus side. So am I doing the right deduction?

 

[notEworthy27]

I've tested the motherboard +5v supply as well, via the pins for the USB port, shows the same reading.

BTW, when I plug in the external HDD, the +5v rail drops to 4.75, but it fluctuates around 4.75 to 4.96v.

 

[notEworthy27]

Confirmed. The PSU is the culprit. Via BIOS voltage monitor, via SpeedFan, +5v rail is at 4.6v. Via tester straight to PSU, all 5v pins were at 4.6v. So I guess its time to replace a PSU if I want to use external HDDs.

Thank you to knightdog56 and luciferano. Helped me alot in understanding my system more.

 

[luciferano]

You're welcome.