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Newbie needs help to power up a cable modem board

Osiris

May 29, 2016
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I took out a working cable modem board from a broken tv cable box. Now without the power board and tv board, i wonder is there a way to power up only the cable modem board so i can use the internet? I am totally new in electronics, could someone please enlighten me? thanks.

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davenn

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Sep 5, 2009
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hi there

welcome to EP

first thing for you to do would be to google search for a service manual for the tv the board came out of
then you will be able to identify the connector pins to find out which ones are power and signal rails

without that info ... you plan wont come to fruition

Dave
 

Osiris

May 29, 2016
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Thanks for your help. Unfortunately i can't seem to find service manual for this specific thomson dvr. There may be other similar models i need to seek. Is there a way to trial and error?
 
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hevans1944

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Jun 21, 2012
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Does your cable TV service offer an internet connection? Mine does, but it is an extra-cost "feature" that is available with or without TV channels. I purchased a high-end cable modem after purchasing the cable internet service, saving the monthly rental fee charged by my cable service provider. Now they have decided to "digitize" the TV channels and add a "decoder" between the cable and the TV. At first these were offered for "free" but now I find out they are going to charge a monthly rental. So, it looks like I will be canceling the TV part of the cable service and erecting an outside antenna for over-the-air digital TV. Still need my cable modem for internet, and the monthly fee charged by the cable service provider for an internet address the cable company (acting as an ISP) provides.

I suggest you either rent the cable modem from the cable service provider, or purchase one of your own.
 

Gryd3

Jun 25, 2014
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Please note that a TV Cable Box is not he same as a Modem that you get your internet from!

The modem that you have been suggested to 'buy' or 'rent' is responsible for providing a physical interface you can use with your equipment in the home. This interface is almost always Ethernet and is used to plug in computers, switches, hubs, routers, Wireless Access Points, Game systems, etc... Almost everything uses it.
The devices that don't are typically on WiFi like the hand-held game systems, cell-phones, and some smaller netbook computers.

So.. even *if* this cable box happens to connect to the 'internet' through your cable provider, you need some way to interface to it. It's highly unlikely that you can simply tap into a couple pins and get internet...
*if* the device uses *internet* it will most likely use different signalling internally among it's components.

Additionally... Let's call you an incredibly lucky person.
If you do happen to connect your PC to it for network access, it will most likely require a lot of tweaking on your OS, or building a dedicated converter box to provide a suitable interface/signal to the computer. You may very well find yourself in a *private* network segment used by your cable provider that has no *internet* or very restricted access. Additionally, if your access is logged or detected, your cable provider may immediately terminate your current and future access.

Internet requires a subscription to a provider. You can't get it for *free* unless you steal it, or break the Terms Of Use for a related service you may already have.
 

hevans1944

Hop - AC8NS
Jun 21, 2012
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Internet requires a subscription to a provider. You can't get it for *free* unless you steal it, or break the Terms Of Use for a related service you may already have.
Well, thanks for that. I didn't want to come right out and accuse the OP of trying to steal Internet service. Then I went back and read:

I am totally new in electronics, could someone please enlighten me? thanks.
So here is some enlightenment: Every Ethernet connection requires a MAC address. This is hard-coded into the cable modem and into every device that communicates via Ethernet. Ethernet is a CDMA (Collision Detection Multiple Access) network hardware communications protocol. It is not the Internet.

Most cable TV companies use a broadband coaxial cable (or fiber optics cable) with hundreds of radio frequency (RF) channels that they assign to particular TV channels, not necessarily on the same frequency as the over-the-air broadcast frequency. Some channels are left over, and these can be used for Ethernet digital communications via a cable modem. The output of the cable modem is Ethernet, but the input could be anything, including digital signals instead of RF signals. My home system cable modem "bonds" two adjacent RF cable "channels" to create a 20 megabit per second Ethernet download stream and a 2 megabit per second upload stream. If I want to upgrade to more bandwidth, my modem is capable of "bonding" several more cable "channels" to obtain it. And if I want to pay really big bux, the cable company will provide a symmetrical Internet connection. The key here is "pay" because they don't offer their services for free.

In addition to the hardware MAC address used to identify Ethernet nodes on an Ethernet network, everything that communicates via the Internet also has an Internet Protocol or IP address that points to the Internet node that is exchanging data via the Internet or World Wide Web. IP addresses are currently 32 bits assigned by international agencies (for a yearly fee) in blocks. See ICANN for more details.

An Internet Service Provider (ISP) purchases a block of IP addresses and re-assigns them either statically or dynamically to their customers. These IP addresses are binary numbers, mostly unrecognizable to ordinary human beings, that are translated by a DNS (Domain Name Server) into URLs or Uniform Resource Locators. Each ISP hosts a domain name server (DNS) that recognizes a particular IP address and communications protocol and translates that to a character string (the URL) that is (more or less) understandable by a human being. The DNS communicates with other DNS to keep their translations tables up to date. For example, https://www.electronicspoint.com is the URL you send messages to and receive messages from when you use this Forum. Think of that as the "front door" to Electronics Point. It is, for reasons I won't go into, likely a static IP address but it still uses a DNS, provided by the ISP serving Electronics Point, so you don't need to know what the "real" IP address is. Appended to the URL is the complete path name to whatever file is being transferred via the Internet or World Wide Web.

So, "getting on the Internet" is a bit more complicated than hacking a TV box that had a cable connection. I have a dynamic IP address that I use to connect to the Internet. It is assigned to me, as needed, by my ISP who happens to be Time Warner. I also own two other URLs, http://www.hebe.net and http://www.hebe.org that are assigned to the same server by another ISP not associated with Time Warner. When either URL is typed into the address field of an Internet browser, both URLs are translated by DNS to the same IP address.

If you want to learn more about the Internet here is a link to a good place to start. It has many other links to other resources for a more complete explanation. It is not necessary to understand electronics to understand the Internet.
 

Osiris

May 29, 2016
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Does your cable TV service offer an internet connection?
Yes, it does. The tv box comes with free internet on it via this cable board and since most ISPs in my area are already on fiber network, it's probably useless to pay for cable anymore. If i can get this board up and running, i would have an extra internet connection to work with.
 

Gryd3

Jun 25, 2014
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Yes, it does. The tv box comes with free internet on it via this cable board and since most ISPs in my area are already on fiber network, it's probably useless to pay for cable anymore. If i can get this board up and running, i would have an extra internet connection to work with.
Well... In any case.
I would suggest looking very closely at the BCM3349 KPBG
> https://www.broadcom.com/products/broadband-access-and-modems/cable-(broadband)/bcm3349

It actually has outputs for a 10/100mbps ethernet connection that your computer can work with.
I won't be supporting this project any further though.
 
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