Post by: spillage on February 18, 2004, 12:53:00 PM
By Spillage
There are a number of ways to provide auto switching operated by the XBOX. However the simplest way to do it is externally. An internal solution is totally feasible but you will have to either interrupt the audio and video going to the AVIP or remove the AVIP socket from the mobo as I have done and redirect it via the switcher.
I have always been a fan of high quality medical grade relays rather than a solid state solution for projects like this one. Many AV amps and processors use them to switch both audio and video and I chose to use three such devices in my own XBOX. This project does not call for this expensive type of relay as we are only switching composite video. I have, however specified a relay utilising gold contacts as it will be used to switch very small voltages. In my XBOX, as outlined in the forth coming tutorial, I have used medical grade relays because I am switching Component and RGB signals thus warranting a better product.
Another video switcher I am working on, uses solid state switching to increase bandwidth. This is however not designed to fit in the XBOX but be an accessory to my TAG McLaren pre-amp. It will be used to switch between six component/RGB devices. This is not currently; something I plan to post unless it is demanded as it requires a self build PCB and complex shielding.
What is described here is fairly crude, but works and needs only minimum disruption to the XBOX.
What is it and what will it do.
This tutorial will assist you in building a simple and cost effective remedy for running an XBOX and a DVD or VCR etc on a TV with a single SCART connector. The device will automatically switch from XBOX to DVD or VCR as soon as the XBOX is switched OFF. The current design is suitable for Composite video only.
This is of particular use to XBOX users with no DD/DTS decoding equipment and an early TV with a single AV input.
To complete you will require:-
Soldering skills and iron.
Basic tools of the average modder. Drill cutters etc, including a multi meter.
I have explained how to do this externally as the internal method is somewhat overkill for what you want.
You will need the following components:-
Websites
CPC [www.cpc.co.uk]
Maplin [www.maplin.co.uk]
1. A standard Composite/Stereo Audio for the XBOX (Yellow/White/Red Cable)
2. A small metal box. (Plastic will do but is not as good as metal for screening reasons) -- CPC Code EN55063 (Metal Die Cast Screened box 80mm x 55mm x 25mm) Buy bigger if you wish.
3. A Scart lead to cut in half or a Scart plug and some screened multi core video cable -- Scart Plug (CPC Code CN06215) Screen AV Cable (Maplin Code XS41U)
4. Two DPCO high quality relays (Double Pole Change Over) and two diodes for back EMF protection.* -- CPC Code SW00990 (DPCO gold contact relay) Maplin Code QL76H (1N4004 x 2 diodes)
5. A short length of thin two core wire.
6. A DC type power plug and socket. This will allow you to remove the AVIP lead and the Relay power lead from the XBOX completely. CPC code CN04152 (Socket 2.5mm) CPC Code CN05725 (Plug 2.5mm)
7. A 250mA fuse 20mm and in line fuse holder insulated. Maplin Code PC78K (Fuse holder In-Line) Maplin Code GJ84F (250mA quick blow fuse.
8. IF you are going to install an LED or LEDs to show status, you will need a suitable LED (Bi-colour) or pair of LEDs. Choose whatever colour you want. Make a note of there requirements. The appropriate LED holder /s for panel mounting provides a more professional appearance as well as a decent mounting.
Alternative components can of course be substituted for those I have listed.
* When a relay is energised a magnetic force is generated. This force is used to pull or push a lever that in turn closes a pair, or multiples of, contacts. When the relay is disconnected from its supply the magnetic field around the coil collapses. The collapsing field induces a considerable voltage or Electro Magnetic Force in the coil thus creating a surge. This surge can destroy components that come before it. Protective diodes are only really needed when a relay or solenoid is driven directly by a transistor. The relays in this project are being driven directly by the XBOX PSU so diodes are not really needed. However, in order to prevent possible damage to the PSU the diodes should be installed as shown in the diagram.
Method.
The finished length of the cables is dictated by your desire to have the XBOX DVD combo close to or far away from your TV.
1. Cut the XBOX AVIP cable to the length you want and bare the yellow/red/white ends to reveal the signal (coloured sheath) and the screen.
2. If you choose to use a complete Scart cable, cut it down to the desired length. If making your own see **.
3. Open the Scart plug and check to see what colours are soldered to pins 2, 6 and 4 (Audio). Pins 20 and 17 ( Video) Make a note of the colours.
4. Bare these colours only and cut off the others. You end up with six individual wire components. A composite and screen. An audio left and right and corresponding screens. If the Scart cable uses a common paired screen for audio then obviously you will have 5 individual wire components.
5. Open up the metal box and drill holes for an IN for the AVIP, an IN for the DC power cable and an IN for the DVD player cables and an OUT hole large enough for the Scart cable to pass through. Make sure you dress the holes smooth, totally removing any roughness that could cut the cables. Ideally use appropriately sized grommets in each hole to protect the cables. Take the stock phono/RCA cable from the DVD player and cut off the yellow/red/white plugs. Bare the ends to reveal the innards as before.
6. Disassemble the metal box and with a screwdriver roughen the surface to provide a key for gluing. Glue the two relays in the middle of the box upside down. I.e. the pins are facing up.
7. Each relay will have eight pins. Two at one end and six the other. Solder two short lengths of wire between the coil pins of the relays as shown in the diagram. This is a parallel connection and will ensure that both relays close and open at the same time.
8. Using a lot of care drill a suitable sized hole in the rear panel of the XBOX. Locate the hole somewhere out of the way of other circuitry and framework inside the XBOX. To do this you MUST strip the mobo from the XBOX. This is easy to do and should take no longer than five minutes. Disconnect the ports and daughter board if you have one. Drop the PSU and the fan connector. Remove all the T10s (TORX) and pull out the mobo. Remove the two T10s from the PSU and remove it too. Now you can pull out the metal screening from the case. Drill the hole for the DC power plug in the rear of the case. Clean up the hole.
9. Refit the metal screening and make sure that it is seated correctly. From the rear, and looking through the hole in the case plastic, mark the metal screening for drilling. Remove the metal screening and drill the hole oversized such that the securing nut of the DC power socket can be tightened onto the case of the XBOX through it. Solder a 20cm piece of the 2 core cable to the DC power socket. Insulate the solder connections with sleeving NOT tape!! Refit the metal screening and install the PSU and mobo. Simply reverse the extraction procedure.
10. You should now have an XBOX case with a DC power socket on the rear and a piece of cable with nowhere to go. Take the wire up to the HDD power loom. Make the connections to the 12v side of the cable via a 250mA quick blow in line fuse. You can determine which of the red or yellow cables is 12v with a multi meter. The black next to the cable you locate is the corresponding ground connection. Again it is important to correctly sleeve and insulate these connections. Tape is not good enough and poor practice.
11. Make up a power cable using the DC power plug and a length of the 2 core cable used earlier cut to the same length as the AVIP cable you cut before. The DC power plug has only 2 connections, which is nice, the centre and the larger outer. As with the socket, make the positive connection on the centre and the negative on the outer. Make sure you insulate your connections properly.
12. Pass the DC power cable through its hole in the metal box and solder the wires to the relay coil pins. Use a tie strap or zip tie to secure the wire from pulling out. At this point you can test and confirm the NC and NO connections on the relay. You will need a multi meter for this test. With the XBOX switched OFF check for continuity between the pins on one of the relays.
13. The relay has a pair of contacts called NC and NO. This means normally closed and normally open. Locate, using the multi meter the pins on one of the relays that indicates a normally closed reading. I.e. The multi meter reads full scale, if analogue or more or less 0.00 if digitala short circuit in other words. Draw what you see for use later in the wiring. Switch ON the XBOX and you should hear the relays click. Measure the pins you found to be NC, they should now read open circuit. With XBOX still ON check to confirm that the pins that were NO when the XBOX was OFF now read a short - right??? Switch OFF the XBOX and the relays will click again and return to the reading you had in the first place.
14. Unplug the lead form the XBOX. Put the lid back on the XBOX making sure you dont trap any wires from the DC power loom and the HDD. Be sure that the fuse holder does not become trapped as you replace the XBOX lid.
15. All that needs to be done now is to make all the connections inside the metal box from all the cables you have assembled. The Diagram explains this best. Basically connect the DVD player Audio and Video centre conductors to the NC side of the relays, as shown. Leave the screens for now. Connect the AVIP Audio and Video centre conductors to the NO side of the relays as shown. Connect the Audio and Video cables from the Scart to the Pole pins as shown. The Audio and Video screens should be connected like for like.
16. Audio Screens. Solder the 2 screens from the AVIP cable and the 2 screens from the DVD cable together. Connect this bunch to the single or pair of audio screens from the Scart plug cable. Be sure to insulate with sleeving.
17. Video Screens. Solder the single screen from the AVIP cable to the single screen from the DVD cable together as before, then connect to the single screen from the Scart plug cable. See diagram.
18. Double check the connections. Use zip ties or tie straps to secure the cables inside the metal box and refit the lid.
** If you have chosen to purchase the Scart plug and multi-core screened cable separately, you will need to make the following connections in the Scart plug.
Composite Video IN on pins 20 (signal) and 17 (screen) Audio IN on pins 6 Left (signal) pin 2 Right (signal) and both screens to pin 4.
Plug the Scart into your TV, the DVD cable into the DVD player and of course the AVIP and DC cable into the XBOX. With your TV on the AV channel play a DVD with the XBOX switched off. You should, if all is well get a picture with sound. Switch ON the XBOX and the DVD picture and sound should be replaced with the XBOX boot up screen etc.
Job done.
As is usual with this kind of modification, read the tut first and understand what it says. Only carry out a modification if you know what you are doing. I accept no responsibility whatsoever if you damage your XBOX and accompanying peripherals. If you have issues PM me.
Spillage.
Post by: Dan Wysocki on February 19, 2004, 03:53:00 AM
Just as a thort...being a cheapass..is there anyway to do this mod without cutting apart the AVIP cable?? Im a clumsy S.O.B sumtimes and without much cash (or any atall
) i dont really wanna risk screwing it up at the mo....unless of course there is a uk modder who wants to buy an xbox live subscription off me 
....Wicked tutorial...look forward to doing it as soon as i pic up sum relays....
Post by: Dan Wysocki on February 19, 2004, 05:52:00 AM
:1
2
3
4
i apologise for the long list, any help with suitability would be great
kudos for the detailed tut!
Post by: spillage on February 19, 2004, 09:33:00 AM
Post by: Dan Wysocki on February 19, 2004, 11:29:00 AM
| QUOTE (spillage @ Feb 19 2004, 07:33 PM) |
| Yes mate, any of those DPCO relays will do the job. You don't have to butcher any cables if you don't want to but you will need to buy some phono sockets to install in the little box. You can get them from CPC as well and are very cheap. I would not bother buying a SCart socket though if you choose do socket everything as Scart cables can be bought really cheap so cutting one in half is no big deal. Let me know how it works out for you. |
wicked, im working on gettin sum £££ at the mo...i have sum phono sockets i can rip outta an old adaptor i had
its good 2 know i dont have 2 rip apart my AVIP cable 2 . Thanx for this quality tut and ill be sure to let you know how i get on when I (eventually) get the bits and do it, hopefully it should b within the next 2 weeks tho coz im sick of having 2 swap scarts so much 
thanx again, i hope uve submitted this as a tut to x-s?
Post by: spillage on February 19, 2004, 01:33:00 PM
