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Could a standard cheapo V box damage my TV

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Old 06-11-2009, 5:07 PM   #1
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Unhappy Could a standard cheapo V box damage my TV

I have the standard minimal cost V box; the ugly grey thing. Shortly after it was installed my TV picture failed. It was a 25yo Mitsubishi so no big deal and I bought a new Sony Bravia W5500. Within a week I kept getting short-sharp tzzcccch noises from the sound of the TV and it began shutting down of its own volition. Again no big deal as I have a 5y warranty and it was changed for a new one. But the replaced TV was only here 2 weeks and it did a couple of tzzccchhh noises and now won't work at all. When I went to unplug everything I got a shock off the V box. The Sony TV diagnostic blink code (for those in-the-know about such esoteric stuff) is 14 which I googled to be an HDMI fault. But the only connection between the V-Box and the TV is the scart as the cheapo V box only has that (or can I use the Arial lead???). I googled a scart wiring diagram and saw no voltages on either of the 21 pins that IMHO could 'blow' anything on the TV but I'd like some guru opinion on that if anyone out there could put my mind at rest as I have the second replacement TV arriving Monday... oh and Virgin are coming to change-out the V box also just-in-case... but I'd like to know if any stray voltages could had caused the damage to the TV's... or maybe if there are signal isolators I could put between the V-box and the TV... or is that abit too paranoid? Thanks in fwd appreciation of any help.
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Old 06-11-2009, 6:09 PM   #2
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Re: Could a standard cheapo V box damage my TV

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When I went to unplug everything I got a shock off the V box
That's bad news.
I would say there is every possibility the box has caused the problem with the telly.
You're correct in saying the scart shouldn't carry any large voltage, but if the box was live, there's a good chance the scart was too, imo.

I certainly wouldn't say anything about it to the people who sold you the telly.
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Old 07-11-2009, 2:03 AM   #3
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Re: Could a standard cheapo V box damage my TV

I agree with what the above post says,certainly seems like that Virgin box is causing the trouble, having said that I have sometimes had a static shock from them in the past,when tinkering but of course yours might be more serious than static ...Virgin did at one time fit isolaters as a matter of course,not sure if they do now though ...I too would endorse you saying nothing to the tv firm about that box problem ...think it goes without saying do not connect that box to the replacement tv,let virgin do the setting up with the new one ....

Last edited by telecom69; 07-11-2009 at 2:06 AM.
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Old 07-11-2009, 4:38 AM   #4
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Re: Could a standard cheapo V box damage my TV

The V box itself can damage other equipment attached to it. This usually happens if a surge occurs and a surge suppressor isn't present where the cable feed comes into your home. Any surge will be passed on through to equipment attached to the STB. Even if no surge has occurred and a surge suppressor is fitted, any other electrical short or fault can be passed from thebosx to attached devices.

Get the box checked out before connecting anything else to it. VM are culpable if the box is at fault and it is there responsibility to rectify the fault and recompense you for any damage it has caused. If they do admit to a fault then get it in writing from them.

Not sure if this is a case of the suppressor being omitted, but I've heard at least two instances where its omission has caused damage to external equipment attached to the STB. I can also state that the suppressor was omitted from my installation, but I was lucky enough to not have a surge and have a engineer notice its omission and fit one. There seems to have been a period when some of the installers skipped the fitting of the suppressor? The engineer who discovered the omission called the installer responsible a "lazy bastard".

The thing is though, if a surge occurs and the suppressor is absent then it blows the STB so it is unlikely to be a surge in your case.

Last edited by dante01; 07-11-2009 at 4:48 AM.
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Old 07-11-2009, 9:46 AM   #5
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Re: Could a standard cheapo V box damage my TV

Thanks to all for the input (excuse the pun). I certainly won't connect this present v-box to my replacement tv. But, is there anything I can place between the new v-box and the new tv just to be on the safe side? I was thinking of a signal isolator or something. Or maybe one of the scart things that you can plug 1,2,3 or 4 scart connectors into (and which has its own power supply) and a single scart run-off to the tv... would this isolate any surge from the v-box? Also how do I (if at all possible) check if the suppressor is in the v-box... can I open up the v-box assuming it doesn't have 'defeat' screws. Lastly, if I upgraded and got the v+ box option and used HDMI would that be better/safer as the tv supplier has said this is my last change-out under the warranty. Thanks again to all.
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Old 07-11-2009, 12:58 PM   #6
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Re: Could a standard cheapo V box damage my TV

Quote:
Originally Posted by 9nine View Post
Thanks to all for the input (excuse the pun). I certainly won't connect this present v-box to my replacement tv. But, is there anything I can place between the new v-box and the new tv just to be on the safe side? I was thinking of a signal isolator or something. Or maybe one of the scart things that you can plug 1,2,3 or 4 scart connectors into (and which has its own power supply) and a single scart run-off to the tv... would this isolate any surge from the v-box? Also how do I (if at all possible) check if the suppressor is in the v-box... can I open up the v-box assuming it doesn't have 'defeat' screws. Lastly, if I upgraded and got the v+ box option and used HDMI would that be better/safer as the tv supplier has said this is my last change-out under the warranty. Thanks again to all.
You should never receive a shock from a VM box.

The VM boxes are all double insulated, which means it shouldn't be possible for a failure in the box to give you a shock. If the chassis of the TV or VM box is live this could be what has caused the damage. I would get the mains sockets tested for an earth leakage problem as VM box could become live via the mains socket of the TV thru' the SCART cable.

You could disconnect the earth shield connection on both ends of the SCART cable. With a short cable this shouldn't cause a problem. An HDMI cable would not be any better/safer.
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