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Martin, Technician
Category: TV
Satisfied Customers: 4944
Experience:  Studied video technologies before university. I still fix TV's in spare time.
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I have TV's in a fitness facility on treadmills. They are

Customer Question

I have TV's in a fitness facility on treadmills. They are connected to cable for TV but when the cable company installed new fiber cable the signal isn't recognized and the TV's work intermittently. The TV's are about 9 years old so I was told a chip inside could be replaced to upgrade the board to recognize the different signal. Where do I start?
Submitted: 11 months ago.
Category: TV
Expert:  Jack replied 11 months ago.

Hi , I`m Jack and I will be helping you today

Please note that I am an independent tech. that depends on your positive rating to get paid by this website and I have no control over the phone (or other) offers , they are sent by the website ,not by me but let me know if you`d rather do this on the phone.

That being said , a few questions coming up ;

Please let me know when you are ready to proceed .

Expert:  Jack replied 11 months ago.

Also ,Could you please give me the tv`s model number writtenon the back cover ?

Customer: replied 11 months ago.
The covers are from the treadmill factory, not TV model. I have a picture of the inside board if you want it emailed to you.
Expert:  Jack replied 11 months ago.

Sorry then this is not what i thought

I was thinking about tv`s hung around those machines , not built-in so i will opt out but before i do i must say that the cable`s company explanation seem a bit flaky as far as i`m concerned

A chip ???

Tell them to check their setup , i believe that it is what doesn`t cut it

Good luck and You don`t have to do anything , your question will be reposted for other techs. to see and jump in.

Expert:  Martin replied 11 months ago.

Hi. Most likely those TV do not have QAM or ATSC signal compatibility. They were most likely working before when they were on the coax cable (company usually still run normal analog along QAM on coax). For fiber, they obviously drop normal analog. What you now need is a signal modulator that will bring the signal out of the new cable box to coax (a full featured old VCR can do that if you don't want to buy a dedicated one, it can accept composite).

That kind of signal conversion with TVs is outside of a simple chip change on the board.

Expert:  Martin replied 11 months ago.

The downside of a modulator is that channel need to be selected on the modulator, so every TV can only receive all the same channel at the same time. If you want different channel you need as much tuner (a tuner being the cable box) as channel you want to select.

Customer: replied 11 months ago.
It's still running coax, but the cable company Calles it hotel fiber. It allows channel changes to all the facility tVs without any boxes. Sometimes the signal works and tv is fine but most of the time it's says, no signal. Any newer TV works fine so I was hoping a replacement upgraded part would be a fix. I'm not a Tech so understanding QUAM compatibility, I'm getting lost a bit. But I've heard about it before. They are LCD monitor computer capable flat screens.
They have a part number on the cable input of TDVS-H707F. I found a Dawoo service manual with information to upgrade software etc on the board but again that's over my head.
If you google the TV model you can also see what I'm looking at NV915 Nautilus TV
Expert:  Martin replied 11 months ago.

I see. if they work sometime, then it is not a type of signal problem. Did the signal came up before from the same terminal or was it just comming from a cable from the wall without any terminal at all?

Customer: replied 11 months ago.
It was out of individual cable boxes. I created a mini head unit with selector boxes that allowed individual TVs to change channels.When the cable company installed the new system, it stopped. They have been real helpful actually and I know personally a couple of the manager folks. Test after test revealed the signal was perfect but for some reason these won't work. But if I hook up any other TV it works fine.
Expert:  Martin replied 11 months ago.

i wonder if it is not a case of newer TV being more sensitive to the signal. If the new signal is a bit weaker, perhaps the old one just can sync on it. If they all have a cable box it would be unlikely but if they just re-route a primary signal perhaps a booster of a signal adjustment from the cable company would help. To test this you could try one problematic TV with all other disconnected (not just off, physically disconnected).

Customer: replied 11 months ago.
Did the booster, actually made it worse.To clarify..... they were working when I had several cable boxes but now that it's a direct line they stopped.
Expert:  Martin replied 11 months ago.

Were the box active (with their own power supply) or just a mechanical switch. Working with more box really look like they are lacking signal strenght. A cable technician would be able to tell you if the dB amount of the signal is right. Perhaps the booster was set too high or simply was not adapted to the required bandwith (in that case it can filter out many needed harmonics in the signal).

Testing disconnecting all unit except one would really help in troubleshooting this.