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View Full Version : Glutton for punishment


smutek
12-01-2013, 08:40 PM
Figured I'd try making this work again, today. No luck, more wasted time.

I've got a Sabrant USB-2011 adapter, Macbook Pro, early 2011, fresh install of 10.9, and running the latest Display Link driver, version 2.1

2 Dell 2209WA Monitors.

Monitor 1 - connected via DVI to thunderbolt adapter.

Monitor 2 - connected via DVI to Sabrant USB-2011

The unit worked fine the first three days that I had it. I unplugged my laptop, took it out to go to a meeting, brought it back home, and the Sabrant connected monitor ceased working.

Monitor 1 Works.

Monitor 2 shows a black screen. The monitor will work for about a minute after uninstalling an reinstalling drivers, then goes black and will no longer work.

Monitor 2 shows up in system preferences / displays. The light on the monitor is blue, indicating it is connected. Also, note the attached screen shot - the desktop is visible (sabrant device on the right)

http://smutekcreative.com/stuff/grab.jpg

But - my screen remains black.

I've tried:


Uninstalling and reinstalling the 2.1 drivers.

Running the 2.1 beta driver

Wiping my hard drive and rolling my system back to mountain Lion.

Wiping my hard drive again and doing a fresh install of 10.9 Mavericks.


No luck on anything.

Any help or suggestions would be greatly appreciated.

Carlo
12-02-2013, 08:20 AM
I've seen this a couple of times before, pretty sure there is not enough power for the adapter. It's a borderline situation: enough power to bring up the chip but not enough power for the DVI transmitter. We are talking tiny amounts of missing power here.

In these cases you may see video at low temperature/just started up and then lose video when everything warms up and the efficiencies drop a bit.
With time however most circuitry tend to lose some efficiency and these setups get worse and worse.

In terms of solutions all the reinstalling and trying new SW is not going to work I'm afraid.
You can try a few things:
- An external powered hub is the definitive solution
- A different USB port, sometimes they have different power ratings
- A different device but how to know which one will use that little bit less power you need?

Hope this helps
Carlo

smutek
12-02-2013, 01:17 PM
Interesting - okay, I'm going to give that a go today. I'll try it first by unplugging all of my connected USB devices and see where that gets me.

Thanks for your response, Carlo.

smutek
12-02-2013, 02:30 PM
I just tried it by unplugging all of my connected devices and running only the displaylink adapter.

It worked for longer than it has since it originally stopped working - about five minutes. Switching USB ports, with everything unplugged, brought it back up for a couple of minutes, then it went out.

I'm kind of hopeful that a powered hub will do the trick and am going to run out and get one today. I'll post back with my progress.

Wish me luck - I really, really, really want this to work. :cool:

smutek
12-02-2013, 06:21 PM
So I went out and grabbed this 4 port, powered USB 2.0 hub from Staples, a local office supply store, (link (http://www.staples.com/Staples-4-Port-Square-USB-20-Hub/product_645448#revs_content)).

My screen fired up for about 5 minutes, then went dark again.

Carlo, if you have the time, would you mind looking at my system profile for this USB port and letting me know if everything looks in order?

http://smutekcreative.com/stuff/grab-2.jpg

I'm not quite convinced as to the quality of this unit however, and I don't know enough about USB hubs to know if it's actually providing power. There are no lights anywhere on this thing, and it just feels cheap.

I'm considering buying a somewhat nicer USB hub and seeing if that works. (Any recommendations?)

Assuming it is a power issue, I'm wondering if it would be worth my while to return this Sabrant and see if I can't find a display link device that's powered?

Am I just chasing my tail at this point - - should I just give up? :confused:

smutek
12-02-2013, 07:19 PM
Well, before I give up I have to rule out the possibility that I may just be using a crappy USB hub, so I just ordered a powered USB 3.0 hub. My machine only has USB 2.0 but this hub that I just ordered uses a 4a adapter so I'm hoping it will provide the power that I need to give to this displaylink adapter. /

The new hub is supposed to give up to 900 mA but it may be a moot point, since the Sabrant uses a USB 2.0 cable which probably maxes out at 500 mA.

I don't know man, if this doesn't work then I may have to throw in the towel.

:mad:

Carlo
12-02-2013, 09:34 PM
Hi smutek,

From your experiments it really looks a hardware problem. You can try to swap cables around but it's likely the device. It's pretty bad news really.

I don't know if you have options for a replacement, it depends on the manufacturer.

If you need to get a new device I can point you to http://www.displaylink.com/shop/index.php

You may want to get a USB 3 device: the new chip generation has better compression even over USB2.

Cheers,
Carlo

smutek
12-03-2013, 02:43 AM
Hey thanks Carlo - that's actually a bit of a relief, to be honest. Sabrant tech support just got back to me tonight and suggested the same, they've offered to do a swap for me.

I just bought the unit fairly recently and may still be eligible to swap it through Amazon. Either way, it looks like I'm covered for either a return or a swap.

Thanks again - I'll do a follow up once I get the USB adapter, then also when I get my replacement.

smutek
12-03-2013, 03:52 AM
I opted to just go ahead and return the device I have now, via Amazon, and ordered a replacement.

I was going to go with a USB 3 device, like you suggested, but all of the vendors I looked at say that the DL-3500 chipset isn't mac compatible. I read reviews that said it works just fine but, at this point, I really don't want to take the chance.

smutek
12-07-2013, 10:10 PM
Everything is working again and I'm a happy camper. I've been up and running for 3 or 4 days now.

Seems the replacement unit did the trick.