[NebUK]

Hi everyone,
My first posting on this very informative forum.
It's a pity I haven't got off to a very good start with my very recently purchased Nebula DigiTV - USB version.
My system is Windows 7 64 Bit with 4GB of RAM.
The graphics card is an Nvidia 9500GT updated to the current drivers, if that's relevant.
I have downloaded and installed the latest drivers from the Nebula website and the DigiTV application v3.7.14.
Everything seems to have installed correctly but all the channels are badly pixelated and the sound is very choppy.
For reference, the signal strength is 75%, SNR 18 to 22 dB (SNR is all over the place) and BER 0.008 (that fluctuates as well)
It would seem reasonable to conclude that my aerial and coax need sorting out BUT, (and here is the frustrating bit) I installed it on another computer (XP on that one), using the same aerial etc and everything works perfectly - great picture and sound.
On that PC the above readings are not wavering about, compared to the installation on the Windows 7 system.
Have I missed something?
Is there a setting I should know about?
Any advice would be greatly appreciated
Thank you in advance

[Bill]

Could be a power supply issue; Some motherboard do not seem to be able to provide clean power to the USB ports. Try a good quality powered USB hub

[NebUK]

Thank you Bill, your solution sounds feasible.
I haven't had a chance to try a powered USB hub yet, but when I do I'll certainly post my findings.
There is another problem now, that may relate.
What do you make of this please?
When I shut down my PC and start it up again it will boot in the normal way, as you'd expect.
However, if I shut down and then switch it off at the main socket, leave it for a few minutes and then switch on - the PC will not boot up; nothing, completely dead as if there is no power going to the PC at all.
At this point the DigiTV box LED is blinking, rather than remaining constant.
Only if I unplug the USB lead from the DigiTV box will the PC boot up normally.
After that, I plug the USB lead back in and the LED becomes constant again - until the next time.
Do you think that adds to the reason for needing a powered hub, or is this something completely different?
Thanks again for your help.

[Batter Pudding Hurler]

Yep. Sounds like power problems. Your PSU may be failing. I would be replaceing that PSU with a new decent one. Spend £40-£70 on the PSU to make sure you get decent quality.

At the very least, nip out and buy that powered USB Hub. If you do a search on this forum on USB Powered Hub you will see lots of people with your kind of problem.

[NebUK]

I would be surprised if it is the PSU failing, it is a good one and in that £40 to £70 range you were suggesting - only twelve months old too.
Everything else on USB works without a problem, including a webcam with a high current drain.
A power problem still sounds like the most probable cause at the moment, perhaps it is the motherboard rather than the PSU.
I can't add much more until I have tried a powered USB hub.

[murrayt]

A part of the question I'm not sure about is what are the differences between the motherboards and PSU's that are in the XP machine and the Win 7 64 bit machine.

I have two USB devices happily running in Win 7 64 bit ultimate (mind you DigiTV V3 plays up a bit in Win 7)

It is an ASUS P5e64 WS Evolution and the PSU is an 850 watt unit with a Q9650 CPU/8Gb RAM with 6 SATA drives. (just as a guide)

[Batter Pudding Hurler]

What happens if all the other USB devices are left unplugged? It may just be pushing the USB side beyond the limit.

[NebUK]

I have tried another PSU, but the problem is exactly the same.
I have loaded another hard drive with Windows 7 and the required drivers only, just in case there was a program or driver conflicting with it on my other installation - no improvement.
I have removed the graphics card and relied upon the onboard graphics - no improvement.
Removed all other USB devices - no improvement.
Next, I wiped that drive and loaded it with XP SP3 - minor improvement, but still terrible.
I will get a powered USB hub within the next few days and I'll give that a go.

[NebUK]

In answer to Murrayt's posting -

The motherboard on the XP computer is an ECS 6100PM-M2 v3.0
CPU - Athlon 215 Dual Core
Graphics Card - Gigabyte Radeon HD4550
PSU - Standard Low Cost 450w

The motherboard on my Vista 7 64 Bit computer is a Foxconn MCP61SM2MA-ERS2H
CPU - Athlon 5600+ Windsor Dual Core
Graphics Card - Gainward Nvidia 9500GT
PSU - Akasa 500W PSU Eco-Friendly Power 80+

I should point out that it now looks less likely to be an issue with Windows 7, so my heading to this thread seems a bit misleading now.
Although it is true to say that the problem appears worse with Windows 7 than it does with XP, but still unacceptable.
Why it would seem a little better with XP could be for all sorts of other reasons.
Despite that, a power problem now seems to be the most likely cause.
Unless someone knows better...........

[Batter Pudding Hurler]

There are a number of other subtle differences between the two machines. ECS vs Foxconn for example. They could of made different choices in the quality of the USB components. Most USB devices are silly little things like Mice, Printers and FlashDrives\Cameras. So the USB Nebula will make higher demands than most.

There are also going to be differences in the power demands of the graphics cards - though that should not really be relevant in 2D mode.

Nice to see an 80% efficient PSU in there. Eco-friendly? So not made from Dolphins like your XP PC.


TBH - A Powered USB Hub has solved so many USB Nebula Hardware problems on this forum I am tempted to get some into stock so I can sell them through this website.

[NebUK]

I am glad you like my Eco-Friendly PSU.
I am getting an Ozone-Caring powered USB hub next.
No that can't be true but you never know, they may exist somewhere.
There is a hub on its way though.
Standby for the next exciting episode.

[Batter Pudding Hurler]

The only down side of the 80% Efficient PSUs is you need to turn up your household heating instead. I was quite happy with my old PCs pumping out so much heat they kept the house warm.

Now, with all these efficient PSUs and silly mercury filled light bulbs, I have to turn on the heating!! Just not right.

[A-Don]

I have a solution for your heating problem Pud; run some distributed computing apps on your cpu and if that ain't enough add in your graphics card.

This has reminded me on a MOD I read about years ago. A fella had water cooled his PC by hooking it up to a household radiator!

[NebUK]

My USB powered hub came today.
Did it work?...........
Yes it certainly did.
Great picture and sound at last.
Signal Strength 75%, SNR 23 dB and BER 0.0000 (No fluctuation anymore)
There may be a number of people out there blaming their poor picture and sound on the aerial and/or coax and all it needs is a powered USB hub to put it right.
It's great to know it works so well with Windows 7 64 Bit too.

For anyone else interested in a reasonably priced powered USB hub -
I decided on a Belkin Powered Mobile Hub (Four Ports) for £12.97 from Tesco Direct online and saved the extra £5.00 postal charge by having it delivered to my local Tesco store (Note: It must be a branch that accepts Tesco Direct deliveries)

I would like to thank everyone for their help and especially to Bill, his suggestion of a powered USB hub in the first reply was spot on.
Although I also take note of BPH's quote a few posts up, "A Powered USB Hub has solved so many USB Nebula Hardware problems on this forum I am tempted to get some into stock so I can sell them through this website."