Bypassing the on/off button on TV question

[Trebeck]

Hey all,

Here's my issue...
On one of my cabs I have to use the remote to turn on the TV.  In another cab I have to hit the power button on my speakers.  I would like to bypass this step and have them turn on as soon as the master power switch is hit.  Now, I haven't started to tear these two apart so what I'm wondering is if someone can perhaps explain a little about what I will need to do or look for when I do crack them open.  I'm pretty good at a soldering iron so I'm not afraid to attempt this myself but I guess I'm just looking for some theory or tips before I begin.

Thanks!

[CoryBee]

On a conversion cab I did a while back I used one momentary switch that was wired to both the Monitor's power button and the Computer's power button.

My $0.02 

[PL1]

On one of my cabs I have to use the remote to turn on the TV.  In another cab I have to hit the power button on my speakers.  I would like to bypass this step and have them turn on as soon as the master power switch is hit.

You can wire the first cab this way using a Double Pole Single Throw (DPST) momentary switch where you add the red wires and green switch in this diagram to your current setup.



If the speakers on cab 2 use a momentary (not latching) switch you can wire it like above.  If 3 items require a button push to switch on, use a 3PST (Three Pole Single Throw) momentary pushbutton. They are hard to find and rather expensive compared to DPST's.

If the speakers use a latching switch, you can use a "smart strip" like this one or the home-built equivalent. (3rd thread below, see last post by yaksplat for details.)

Several related threads:

http://forum.arcadecontrols.com/index.php?topic=118776.msg1277363#msg1277363

http://forum.arcadecontrols.com/index.php?topic=120605.msg1283352#msg1283352

http://forum.arcadecontrols.com/index.php?topic=121356.0


Scott

[nickbuol]

I have 3 swtiches on my cab, but they could be reduced down to two.  They are all on the top of my cabinet, out of sight.

One is an on/off toggle for the marque light.  Nothing to do with your question though.

The other two are just regular "arcade" buttons.  Since they are "momentary" switches, they work perfectly.  I just connected up one to the motherboard of the PC where the power switch would normaly connect.   Easy peasy....

The TV just got the other switch connected to it as well.  This took a little more work but was easy too. Just had to carefully remove the front bezel of the tv, and locate the power button.  Mine was one with easily to follow circuit board traces.  I just soldered the small wires that ran to my arcade switch right to spots on the circuit board that were already exposed (not imbedded into the "green" board itself).  The trick was getting just a tiny amount of solder, but it wasn't too bad.

I would assume that you could do the same with any momentary switched device (speakers, etc).  I used speakers that have a hard power switch, but go to "sleep" when the computer is off.  It still uses a tiny bit of power even in sleep mode, but was the easiest for my install.

[Trebeck]

Thanks guys this is great info.
I'd much rather add on to the electronics than modify existing and I completely understand what you all are getting at.  I have a momentary switch (Master on off) attached to the mobo and the comp is plugged into a smart strip.  Everything else (light, speaker, tv) is connected to the strip and it all turns off nicely but not everything turns on until I figure this out.  I'll just run cable from the tv to the master switch and all should be well.  I'm going to do a little more reading on switches and I should be good to go.

Beck

[nickbuol]

Without doing what I did, no strip was smart enough to turn on my TV.  It has a momentary switch on it, not a "toggle" switch that could be left in the "ON" position and then controlled by a smart switch.

If I ever want to undo what I did, I can simply snip off the wire where it soldered to the circuit board.  No harm, no foul.

[CoryBee]

Without doing what I did, no strip was smart enough to turn on my TV.  It has a momentary switch on it, not a "toggle" switch that could be left in the "ON" position and then controlled by a smart switch.

If I ever want to undo what I did, I can simply snip off the wire where it soldered to the circuit board.  No harm, no foul.

 This 

[PL1]

I'll just run cable from the TV to the master switch and all should be well.

As long as you use a DPST or DPDT configuration, you'll be fine.

Remember that the dotted line between the two switch levers in the diagram is only mechanical, not electrical.

The TV and computer circuits are mechanically connected, but electrically separate.



It also occurred to me that if you were worried about modifying the board, you could scrape back a little insulation and use micrograbber clips to connect.



Method #2 - Connect the power switch on a remote control using the same method above.  Position the remote's transmitter so the TV remote sensor can see it.  Advantage - You never have to decase or mod the TV itself.  Disadvantage - Changing the remote batteries or misalignments between TV sensor and remote.


Scott

[MacGyver]

I think the real thing he (and most of us) are\is looking for is small circuit that uses a 12V/5V molex computer plug, that can be programmed to emit a learned IR sequence out of IR dongle, or\and that controls a small relay that can connect two wires, based on the condition on the 12V/5V lead.  eg. 12V in, then wait 2 seconds and send power+video+volume up+volume up+volume up for an RCA.  And if it used a rechargeable battery or a large capacitor, it could also execute a "shutdown" sequence when it senses the 12V has gone as well.  Like a Smart-Strip mixed with a learning IR remote mixed with a PIC.

I've never seen one here, but I bet Andy knows a source for them.  I know I could use one, and so could Trebeck, hell so could most of use.

[bob800]

small circuit that uses a 12V/5V molex computer plug, that can be programmed to emit a learned IR sequence out of IR dongle, or\and that controls a small relay that can connect two wires, based on the condition on the 12V/5V lead. 

I use a very similar setup on my cab with an "Arduino" microcontroller: http://www.arduino.cc/ Instead of a molex plug, I leave the USB programming cable connected—when the computer turns on, the USB port receives power and thus the arduino turns on, executing my script from the beginning.

The IR scripts can be quite complex to write from scratch, but you can easily find some pre-written for common manufacturers (i.e. Sony, Samsung, etc.).. If you don't care about the "learning" capability, you can just rip out an IR LED from any old remote and solder it to a digital pin and ground on the microcontroller (using the proper resistor, of course).

If you leave the programming cable connected like I did, you can easily send commands from/to the microcontroller using the "Serial" class functions. Once you download the Arduino IDE from the link I posted, have a look at the included code examples. Even if you've never coded before, you'll find it easy enough to cut/paste chunks of code from various examples until you get something working. Use Google!!

I'll be happy to help if anyone has questions\problems with this. Also, if anyone needs a script to turn a Samsung TV on\off, let me know and I can send you my script.

[RandyT]

I take it that your TV is one which does not remember the last power switch state after a power loss?  In this case, you may have a simple option.  It doesn't work all of the time, but it's worth trying.

Unplug the unit, hold down the power switch and plug it back in.  If it comes on and stays on (be sure to wait for a while to make sure it doesn't turn back off after some time), and the rest of the functions on the TV still function normally, use whatever method you are comfortable with to duplicate this.   You can take the unit apart and bridge the switch with some solder, but if appearance and reversibility isn't a concern, you can use some epoxy putty to hold it down.  Just make sure the switch is held down while the putty cures.

Also, make sure that the TV remembers what input it was on after a power loss.  If not, powering on is only half the battle.

Try this with your speakers as well.  You might get lucky.

RandyT

[nickbuol]

That is a great tip that someone shared with me a number of years ago.  In my situation, my TV would lose the memory of which input it was supposed to be on, and more annoyingly, it would bring up a "setup" screen overlay any time that the TV was disconnected from power (power strip turned off) for more than a few hours.

Maybe it will work for the original poster though...

[harveybirdman]

So if I am reading this right (which is debatable) if my TV has a momentary switch and I don't opt for the simulated infrared pulse method and I want to ensure that TV and PC don't end up with conflicting states then I'm stuck with two power buttons?
 

[nickbuol]

Maybe....  Probably... 

Yeah, most likely...

[RandyT]

Epoxy putty?  Lord.  Shove a toothpick on the side and break it off.

Some TV's have tiny buttons with virtually no gap between the button and the bezel.  With those types, you couldn't do that if your life depended on it.  But, whatever works is fine.

[RandyT]

No they don't.   

If you haven't seen too many, you would probably say that.  A number of years back, I dealt with this issue on a roll out of 100 DVD-based 3D kiosks.  We needed to use a particular DVD player which could be computer controlled, and it didn't power up automatically.  The power button was a "soft-touch" switch, which had virtually no throw to it, and no way to reliably wedge it down.  Had to disassemble every one of them and bridge the switch contacts.

But as I stated, whatever gets the job done is fine.

[superbigjay]

Unplug the unit, hold down the power switch and plug it back in.  If it comes on and stays on (be sure to wait for a while to make sure it doesn't turn back off after some time), and the rest of the functions on the TV still function normally, use whatever method you are comfortable with to duplicate this.   You can take the unit apart and bridge the switch with some solder, but if appearance and reversibility isn't a concern, you can use some epoxy putty to hold it down.  Just make sure the switch is held down while the putty cures.

LOL... I know this thread is old like ... 13 years old.
But just wanted to thank you Randy!

I finished my cab in 2007, and my solution for the TV was to have a small hold in the bezel and use the tv's remote to turn it on.
I never really bother to open the tv and bypass/redirect the power button on the cab's control panel.

But lately (last month) my remote's tv stopped working and was looking for a solution.
Then saw this post... I tried it on my TV and it worked!
I simply jammed a toothpick and voilà ... my TV turn's on as everything else when the cab is powered on!

[Zebidee]

I simply jammed a toothpick and voilà ... my TV turn's on as everything else when the cab is powered on!

You can make it permanent by soldering across the momentary switch terminals, like Randy described above. Could even run wires to a throw switch.

For TVs that require the momentary switch to be pressed but then released, like some Loewe TVs I've worked with, put a capacitor (say 10uF or 100uF) across the momentary switch terminals. Make sure the polarity is right way around (+ to active signal/IC, - to GND). Likely easier to put it on the underside of the chassis, no need to disturb anything else.

This cap trick works because while the cap is charging the circuit is closed, like pressing the button. When the cap is charged (usually <1s) the circuit opens again, like releasing the button. The TV turns on.

You can adjust the "press time" by using a larger or smaller cap, or lengthen the time by putting a resistor in series with the cap.

This idea can be useful for "toothpick" TVs like yours too, because most would just need the button pressed - and then released, rather than constantly held down. Might be better for TV in the long run.