Unstable USB power, motherboard or PSU?

[vexa]

I found strange issue with my usb, I think it's underpowered, or the power seems very unstable.

I have usb to slimline sata I've been using with a dvd rom I took from my broken laptop.
it has two usb port, like this: http://www.amazon.com/dp/B00N1QLY50
when I plug both usb to my motherboard, my dvd ROM doesn't work.
Sometimes windows doesn't recognize it at all, sometimes it's detected, but when I insert any dvd it suddenly disconnect.
For the record, it works normally before, and I tried to plug it to my friend's laptop and it works flawlessly too there. even it works with only one USB plugged in.
for now, to make it works, I need to plug one usb port to my MB and the other one straight to power socket using my phone USB charger. It works normally this way.
I don't know if it's the safest option, but I need to use that DVD ROM and have no other choice.

My phone also has the similar issue whenever I plug it into my PC. It's Xiaomi Redmi Note 2.
The charging led indicator is blinking rapidly and unconstantly and windows is unable to detect my phone.
It's like the power from my MB USB is kinda spikey (?) or not stable at all.
I wish i could put it on video and post it here, but unfortunately I have no other camera.

These issues doesn't appear everytime tho. Sometimes my phone and my dvd rom works normally but it's like 80% failed and 20% success all the time.
oh, and other devices I put on my MB USB is working fine. There are:
Logitech keyboard and mouse,
TP Link WN722N usb wifi,
Canon E500 printer,
xbox 360 controller, and
some USB flash drives.
The power issue only appears on my slimline DVD and my phone.

I tried to reinstall my windows, because I thought it was my USB driver. But it doesn't fix. Then I switched my old 600W OCZ modXtream pro with other PSUs: My father's Corsair CX600 and new FSP Hexa 500w and the issue still appears. I know these aren't top notch PSU, but these PSUs works normally on my father's PC and I think it's sufficient enough to test my motherboard.

So, the problem is from my MB, isn't it?
I just want to make sure of it before RMA'd it.

My spec:
ASrock B75M GL R2.0 (2013)
i5 3450 (2013)
OCZ modxstream pro 600W (2009)
FSP hexa 500 (last week 2015, new old stock)
msi 7870 (2013)
128gb ssd (2013)
1tb hdd (2011)

PS: Pardon my bad english.

 

[rohitbaran]

Yes, it seems that it is the issue with the motherboard where one of USB ports seem bad, considering what you have told here. I would like to see what a few other members in the forum say about this though.

 

[vexa]

Yes, it seems that it is the issue with the motherboard where one of USB ports seem bad, considering what you have told here. I would like to see what a few other members in the forum say about this though.

Thanks for your reply.
and I don't think it's only one of them tho. I tried to plug my dvd / phone to any usb port available (both 2.0 and 3.0) and the issue is still there. I've tried to remove all my usb and left only my keyboard and mouse, and tried to plug my dvd / phone and it doesn't work too.
but like I said, it confuses me that my other usb devices works normally.

anyway, I'd prefer to fix it myself tho, RMA will take couple of weeks and I need to use my PC almost everyday.
also holiday is coming means RMA will take more time than usual working day.
so I'd appreciate any solution other than RMA.
and yes, I have no money to buy another MB yet while waiting for the RMA process.

 

[rohitbaran]

Hmm. Can't really say. You have also tried other power supplies, so I think it isn't a psu issue.

 

[tsnor]

MB not PSU supplies power to USB ports. The max power avail at a usb slot depends on what else is using he same (internal, on MB) usb hub. Device manager reports the allocation of power to usb items plugged into usb ports (but you have to look at each usb hub, epand them then look at the power tab). If the device has two usb leads then it need more power than a single usb hub provides. Suggest you plug into two different usb slots until you find a config that works.


if you don't find a working usb config then buy a MOLEX to USB POWER adapter $3 that will give usb power directly from teh PSU. http://www.coolerguys.com/840556096177.html COOLERGUYS 4 PIN MOLEX TO DUAL USB 5V POWER CONNECTER (warning I have never used this part or bought from these guys, just used google to find an example).