Bizarre TV project/question

[[email protected]]

I am currently converting an old sit-down racing arcade game into a
dedicated xbox racing game. I know that probably sounds funny.
Basically what I have is this...I purchased an old arcade driving
cabinet that was gutted. (the original arcade monitor and controlling
circuit board were not in it. The rest of the cabinet was in decent
shape) I refurbished the cabinet and bought a 27" television from
walmart and then took the television out of its plastic casing. I then
modified some brackets and attached them to the television chassis and
installed it into my arcade driving cabinet. It is a perfect fit and
should do the job nicely for what I want. It has rca jacks on the
circuit board for hooking up the xbox to it, so that will also be a
quick job. My current dilemma is that the television's circuit board
has a IR sensor on it so you can operate the television with the remote
controller. Since I installed this tv into another cabinet, I will be
unable to use the remote control since the circuit board is kind of
hidden inside the arcade cabinet now. My question is if it is possible
to desolder the remote sensor off of the circuit board and mount it
somewhere else on the arcade cabinet and just run wires back to the
circuit board? I know that this probably sounds insane, but I need to
have the remote working as I don't think it is possible to get the tv
to switch to AV mode any other way. Any and all help is welcome and
appreciated. I can provide pictures if my explanation isn't clear
enough. Thanks.

 

[James Sweet]

I am currently converting an old sit-down racing arcade game into a
dedicated xbox racing game. I know that probably sounds funny.
Basically what I have is this...I purchased an old arcade driving
cabinet that was gutted. (the original arcade monitor and controlling
circuit board were not in it. The rest of the cabinet was in decent
shape) I refurbished the cabinet and bought a 27" television from
walmart and then took the television out of its plastic casing. I then
modified some brackets and attached them to the television chassis and
installed it into my arcade driving cabinet. It is a perfect fit and
should do the job nicely for what I want. It has rca jacks on the
circuit board for hooking up the xbox to it, so that will also be a
quick job. My current dilemma is that the television's circuit board
has a IR sensor on it so you can operate the television with the remote
controller. Since I installed this tv into another cabinet, I will be
unable to use the remote control since the circuit board is kind of
hidden inside the arcade cabinet now. My question is if it is possible
to desolder the remote sensor off of the circuit board and mount it
somewhere else on the arcade cabinet and just run wires back to the
circuit board? I know that this probably sounds insane, but I need to
have the remote working as I don't think it is possible to get the tv
to switch to AV mode any other way. Any and all help is welcome and
appreciated. I can provide pictures if my explanation isn't clear
enough. Thanks.

Sure, it's easily done. Do be careful though, the TV may be of the hot
chassis design, in which case your remote sensor is floating at line
voltage rather than being grounded so if in doubt, insulate it.

 

[[email protected]]

uuhhh...in english? Sorry, I'm not sure I understand. Are you saying
that to put the sensor somewhere else on the cabinet I might run the
risk of getting zapped if I touch it? If so, what exactly should I do
to avoid arc welding my fingers together?

 

[inty's world]

turn off the tv set, desolder the ir reicever.
take three wires from the PCB (where the three pins of the reicever
were before you undsoldered it) and connect them to the legs of the
reicever (1-> 1, 2-> 2, 3-> 3)...
it's not too insane.. it's insane the xbox-racing-driver :-D

 

[[email protected]]

ok, I guess I follow you. Just so I'm on the same page though...there
are a total of 5 solder points. I'm thinking that the two on the
outside are actually holding the IR sensor to the pcb and the three in
the middle are the brains of the unit??? Right?

 

[Arfa Daily]

I had the same problem, doing exactly what you did.
My tv had a scart, if yours does not it's another problem but a
scart has a pin which can be fed with i believe 12v and will cause
the tv to jump in ext1 mode.
I soldered a relay in series with a capacitor so the relay would
have a delay of a few seconds to allow the tv to start and then the
12v feed kicked in, jumping the tv in ext1 mode.
If that does not work for you, install the IR sensor somewhere
else as mentioned above.
If in doubd, ask a tv technician, it's not too complicated.

Bart Bervoets

As James said, moving the remote sensor is not a problem. However, I would
recommend two additional caveats. First, use single screen twin ( like
balanced mic cable ) to make the connection, using the screen ( shield ) for
the ground connection, and one each of the two inners for the +5v supply
pin, and the data out pin. Second, I would recommend that wherever you mount
it, you make sure that it's still behind a piece of IR filter material to
avoid interference from sunlight etc.( there's also no issue then about you
being able to touch anything ).

Bart's suggestion above is also a very good one, if you only need to go over
to AV, and don't need to get access to other remotely controlled functions.

Arfa

 

[inty's world]

uhm..... if you only want to switch AV follow what "bart bervoets"
said...
or, if you want to use the remote controller..
how much pin does the ir reicever have?

 

[[email protected]]

I think that my best bet is to move the remote sensor elsewhere on the
cabinet as I would like to access all of the remote functions if
needed. It appears that the pins on the sensor are about 3/16" in
length. Soldering should be a little tricky, but not impossible.
Regarding what "Arfa" wrote, I am not sure what you are talking about
with the single screen shield? What is it? What is balanced mic
cable? Where can I purchase it? I thought that I could just use some
telephone wire to extend the sensor out away from the circuit board? I
appreciate all of the help guys, but I need alot of layman's
terminology. (I am a fireman by trade, not even remotely an
electrician or circuit board tech) If you guys could steer me towards
exactly what type of wire to use and where to purchase it (radio
shack???) that would help. Also, where can I get IR filter material?
I tossed out the old tv cabinet a long time ago, so I can't use the old
IR filter off of that.

 

[I.F.]

As James said, moving the remote sensor is not a problem. However, I would
recommend two additional caveats. First, use single screen twin ( like
balanced mic cable ) to make the connection, using the screen ( shield )
for the ground connection, and one each of the two inners for the +5v
supply pin, and the data out pin. Second, I would recommend that wherever
you mount it, you make sure that it's still behind a piece of IR filter
material to avoid interference from sunlight etc.( there's also no issue
then about you being able to touch anything ).

Bart's suggestion above is also a very good one, if you only need to go
over to AV, and don't need to get access to other remotely controlled
functions.

Arfa

If the TV has a live chassis there is another option worth considering -
some retailers sell IRRC remote control extenders, some types use an RF link
so you can mount the set end unit inside the cabinet where your TV chassis
IR unit can see the IRLED and you can put the box that picks up the beam
from your handset anywhere you like. Its a more expensive option but its
certainly safe and avoids modifying the chassis.

 

[[email protected]]

My question is if it is possible
to desolder the remote sensor off of the circuit board and mount it
somewhere else on the arcade cabinet and just run wires back to the
circuit board?

You may find that there is too much electrical noise going on inside
the cabinet to do this. Some IR receiver modules are incredibly
sensitive to interference. I'd recommend using shielded audio or data
cable to do this, rather than ordinary hook-up wire.

If you could run a piece of optical fiber from the receiver to the
cabinet, that'd be even easier, and wouldn't create any interference
problems for you. You can get cheap plastic fibers in six foot lengths
or longer at electronics surplus places. Networking fibers are
available everywhere, but I wouldn't recommend them because they are
incredibly thin and you won't get very good coupling from six feet away.

 

[[email protected]]

I think that my best bet is to move the remote sensor elsewhere on the
cabinet as I would like to access all of the remote functions if
needed. It appears that the pins on the sensor are about 3/16" in
length. Soldering should be a little tricky, but not impossible.

Have you thought about using "mirrors" instead? I use one of the
remote control extenders with my satellite system, but need to bounce
the signal with a mirror as well.

 

[Bart Bervoets]

I had the same problem, doing exactly what you did.
My tv had a scart, if yours does not it's another problem but a
scart has a pin which can be fed with i believe 12v and will cause
the tv to jump in ext1 mode.
I soldered a relay in series with a capacitor so the relay would
have a delay of a few seconds to allow the tv to start and then the
12v feed kicked in, jumping the tv in ext1 mode.
If that does not work for you, install the IR sensor somewhere
else as mentioned above.
If in doubd, ask a tv technician, it's not too complicated.

Bart Bervoets

 

[oldfogie]

ok, I guess I follow you. Just so I'm on the same page though...there
are a total of 5 solder points. I'm thinking that the two on the
outside are actually holding the IR sensor to the pcb and the three in
the middle are the brains of the unit??? Right?

 

[[email protected]]

thank you...that is one of my questions answered. Now I just have to
figure out the best solution for wiring. "stickyfox" suggested optical
fiber for my wiring? I'm not familiar with this and I'm really looking
for something I could just pick up at my local radio shack. I'm
guessing by all of these posts that it must be shielded too? Come on
guys, brainstorm! (think Radio Shack too!)

 

[ampdoc]

I would use microphone cable for a balanced line mike. It has a Copper braid
shield and 2 insulated conductors inside. Connect the braid to your ground
and use the other 2 wires for the +5v and signal. The cable sould be similar
to what they have here:

http://dkc3.digikey.com/PDF/T061/1493.pdf

The cable at the top of that page would work fine, Radio Shack should have
something similar. 2 conductor with shield.

Hope this helps.

 

[James Sweet]

ok, I guess I follow you. Just so I'm on the same page though...there
are a total of 5 solder points. I'm thinking that the two on the
outside are actually holding the IR sensor to the pcb and the three in
the middle are the brains of the unit??? Right?

Yes, the outside two are the mechanical mount though they're likely also
grounded for shielding. The other 3 wires are power, ground and signal.

If in doubt you might want to find someone more familiar with this
stuff, TVs can be dangerous.

 

[James Sweet]

uuhhh...in english? Sorry, I'm not sure I understand. Are you saying
that to put the sensor somewhere else on the cabinet I might run the
risk of getting zapped if I touch it? If so, what exactly should I do
to avoid arc welding my fingers together?

Hot chassis means that "ground" in the TV set is not earth ground, the
AC line coming in is rectified and filtered into around 170VDC, the
negative side of this is called "ground" but in reality it's floating
well above earth ground and you'll get a shock if you touch it. Many TVs
use a transformer in the switching power supply and are isolated but not
all are so it's important to know what design your TV uses before you do
too much mucking around.

 

[[email protected]]

I am trying to find circuit board schematics for this tv on the
internet and have not been successful. It is a Memorex MT2274A set. I
was just looking at the circuit board and specifically at the IR
sensor. I understand that the outside left and right terminals on the
sensor are for mounting purposes. Now the three middle ones I'm not
sure of. If I purchase that mic cable for lengthening this setup, I
guess I'm supposed to solder the braided ground cable from the mic wire
to the "ground terminal" on the IR sensor. Out of the three center
pins, how do you know which one is "ground?" I looked on both sides of
the pcb and there is no markings, and as I said before, I have no
access to schematics.

 

[I.F.]

I am trying to find circuit board schematics for this tv on the
internet and have not been successful. It is a Memorex MT2274A set. I
was just looking at the circuit board and specifically at the IR
sensor. I understand that the outside left and right terminals on the
sensor are for mounting purposes. Now the three middle ones I'm not
sure of. If I purchase that mic cable for lengthening this setup, I
guess I'm supposed to solder the braided ground cable from the mic wire
to the "ground terminal" on the IR sensor. Out of the three center
pins, how do you know which one is "ground?" I looked on both sides of
the pcb and there is no markings, and as I said before, I have no
access to schematics.

Try here; http://www.eserviceinfo.com/

 

[David]

to the "ground terminal" on the IR sensor. Out of the three center
pins, how do you know which one is "ground?" I looked on both sides of
the pcb and there is no markings, and as I said before, I have no
access to schematics.

Do you have an ohmmeter? See which terminal has zero ohms to a ground point
such as the tuner case.
Are you sure you are not in over your head?

David