Where is the +5V power of UD3R's USB port from?

[onemilimeter]

Where is the +5V power of UD3R's USB  port from? Is it from the +5V of the 24-pin motherboard power connector? Or, is it stepped down from the +12V?

Thanks.

[Dark Mantis]

It comes straight off the 5v line as far as I am aware, what would be the point of stepping it down after reaching the motherboard when there is a 5v supply available.

[onemilimeter]

It comes straight off the 5v line as far as I am aware, what would be the point of stepping it down after reaching the motherboard when there is a 5v supply available.

My wife got a laptop she bought two years ago. Before I purchased the UD3R board, I got an old P4 system (it's almost death now) with Gigabyte 865PE motherboard which was bought in 2004. I've a WD Passport 250GB (WDP250) and two USB Y-Cables (denoted as Cable-A (0.7m) and Cable-B (1.0m)). When Cable-B is used to connect the WDP250 to the computers, the WDP250 works fine. However, when Cable-A is used, the laptop and P4 "see" the WDP250, but the UD3R does not "see" the WDP250. I thought that the UD3R's USB port, if not better, should be at least as good as the old Gigabyte motherboard bought in 2004. I'm not sure if I miss out any UD3R settings.

[Dark Mantis]

I think that I follow what you are saying but I can't understand why it should be. You have checked that the cable is still working? It's just that I would have thought that one side would be powered maybe and the other not.

[onemilimeter]

I think that I follow what you are saying but I can't understand why it should be. You have checked that the cable is still working? It's just that I would have thought that one side would be powered maybe and the other not.

Some test results here...

*****************************
[Not Working]
WDP250 -> Cable-A -> UD3R

[Working]
WDP250 -> Cable-B -> UD3R

[Working]
WDP250 -> Cable-B (without connecting the "power-only" cable to another USB port) -> UD3R
*****************************

*****************************
[Working]
WDP250 -> Cable-A -> Laptop (bought in 2008)

[Working]
WDP250 -> Cable-A (without connecting the "power-only" cable to another USB port) -> Laptop (bought in 2008)

[Working]
WDP250 -> Cable-B -> Laptop (bought in 2008)

[Working]
WDP250 -> Cable-B (without connecting the "power-only" cable to another USB port) -> Laptop (bought in 2008)
*****************************

*****************************
[Working]
WDP250 -> Cable-A -> P4 system with old Gigabyte motherboard (bought in 2004)

[Working]
WDP250 -> Cable-A (without connecting the "power-only" cable to another USB port) -> P4 system with old Gigabyte motherboard (bought in 2004)

[Working]
WDP250 -> Cable-B -> P4 system with old Gigabyte motherboard (bought in 2004)

[Working]
WDP250 -> Cable-B (without connecting the "power-only" cable to another USB port) -> P4 system with old Gigabyte motherboard (bought in 2004)
*****************************

[Dark Mantis]

No argueing with that, very nicely laid out. I really don't know why that should be because if anything I would have expected it to work better with a new style motherboard than the old P4. Sorry.

[onemilimeter]

No argueing with that, very nicely laid out. I really don't know why that should be because if anythin I would have expected it to work better with a new style motherboard than the old P4. Sorry.

From visual inspection, I would say the built quality of the Cable-B (although it 30cm longer) is better than that of Cable-B. This may be translated into that the Cable-B has better shielding. Please correct me if I'm wrong. If what I think is correct, then the "signal" output by the UD3R seems to have lower quality than the older motherboard and thus due to the lower quality of Cable-A the WDP250 does not work. But like you say, I expect the new UD3R should be better in this aspect compared to old motherboard.

[Dark Mantis]

Possibly, but it is just pure conjecture. There is no evidence to back it up only that the facts fit the theory.