How-To: TVandNav2Go install – Part 1 (modding the NAV unit)

[jhelmuth]

Preface: This portion of the TVand Nav2Go mod is not suited for anyone who does not feel comfortable in making circuit board “cuts” and soldering in “micro” spaces (traces and components with very small widths and surfaces). If you are not experienced in soldering micro components, I strongly urge you to consider having this mod carried out by someone with experience – or send your unit into Dominic at TVandNav2Go.com.
This part will be a multi-part post to accomidate all the pix and text


Difficulty (scale of 1 to 10 with 1 = easy): 8



Time requirement: ~ 1 and ½ to two hours.




Tools you’ll want to have…


I’ve inadvertently left out the soldering iron in the pix. You’ll want a medium wattage iron with a nice fine pointy tip. If you don’t have one, you should consider picking up a 25-watt pencil (Radio Shack model Cat # 64-2070). Blunt tipped soldering irons may prove to be difficult or unusable given the small sizes of the surfaces and spacing between components and circuit board traces.

Note: I’d advise using magnetic tipped screw drivers to avoid inadvertent lose of a screw and for ease of re-assembly.

[jhelmuth]

Step 1 – Remove Nav unit from console



I’ve simply posted a link to another FAQ here that I used to help me pull my NAV unit out. It has good pix and is accurate. I did note that my hands were a bit large for getting behind the A/C controls to unplug the connectors. Once you accomplish that, the rest of the removal will go pretty easily.

[jhelmuth]

Step 2 – Remove Front Bezel from the Nav Unit



[1] Move the Nav unit and your tools inside or to any comfortable well lit working area. If you have the TVandNav2Go instructions, you may find (like I did) that you do not have to remove the top and bottom covers of the NAV. Simply removing the front bezel itself is sufficient and I had no luck in removing the top and bottom covers from the NAV unit (my unit was dated January 2005).

[2] Pull off the 3 front knobs (Vol/Tune/joy-stick). They pull straight off with a mild tug. Make a mental note of the joystick orientation for easier re-assembly, as this is the only knob of the 3 that has a definite orientation! Set aside for re-assembly later.

[3] Now remove the 4 tiny top and bottom (2 each) bezel screws (you need a tiny Phillips screwdriver to do so – size #0 or #00 I believe).

[4] Next remove the 8 side screws (4 each side) using a #1 phillips screw driver

[5] Now, by gently prying up from the back edge of the bezel where the little square holes are located in the top and bottom only, you can then remove the bezel front relatively easily, exposing the NAV display and control circuit board (mounted behind the bezel).

[jhelmuth]

Step 3 – Remove Display Circuit Board assembly



[1] Remove the 4 phillips pan-head screws which hold the board in place (see arrows in pix showing their location on one side).


[2] Carefully pry it forward (away from the mounting) detaching it from it’s connectors on the back side.

[3] Once removed, you’ll note that there is a small black wire harness that has a micro connector attached to the board – remove that from the board by carefully wiggling it from its socket.




OK – now you should have the display assembly free and ready to do some modification work by cutting 4 traces (1 under the display it self of the front of the circuit board, and 3 on the back of the circuit board at the connector close to the long slot opening in the board (access to the Nav DVD reader).

[jhelmuth]

Step 4 – Routing the TVandNav2Go Interface cable



[1] Take the interface cable (black casing with a DB-9 connector on one end) and “thread” the cable through any appropriate opening in the Nav unit casing such that you can easily route the colored wires to the Display Assembly without much trouble (you may want to use the routing I chose – see pix).


[2] While not necessary, I attached a tie-wrap to the end as a strain-relief

[3] Pull enough of the cable through to allow easy manipulation and attachment in the proceeding steps.

Note: to make routing easier, I removed the 9 screws from the front display assembly mounting plate. You may decide it works for you as well, but is not necessary (or you may choose to rout your cable differently than mine).

[jhelmuth]

Step 5 – Modifying the Sync/Green/Red/Blue signal traces



[1] We’ll start by doing the most difficult one first (the Sync signal trace located under the display).


a) Flip the assembly over onto its face (put down a nice static free mat or a static fee plush cotton hand towel to avoid any potential damage to the display).

b) Remove the 4 phillips head screws that mount the display screen to the circuit board. There is also an additional solder mount that must be un-soldered (near screw mount #4) to remove the screen. You can probably get away with just heating it up and wriggling it out, but I used some solder wick (recommended – see pix of tools) to make it clean and easy for re-assembly.

c) A flat mylar ribbon interface “cable” remains attached to the display screen AND the circuit board. This may be removable, but I did not attempt to do so as it was not necessary and I observed that the connector had some sort of white compound that may be a “glue” (or at least an anti-tamper material). Removing it looked as if it would make the job easier, but to avoid any potential damage I opted to not attempt removal.

d) Simply sliding it above the area where the sync trace is located (see red box in the pix) will expose it sufficiently to allow the necessary work.

e) Taking your box-knife cutter, carefully “cut” the trace between the ends as indicated in the pix. You will also want to remove the “blue” covering material from the area you cut as well as at the ends of the trace where you need to solder the sync wires (1 brown and 1 grey). Look carefully at the pix – you will notice that I created a “testing” pad at the cut to validate my connections (using a multi-meter).

f) Placing your multi-meter in “continuity” mode (Ohms reading), test the trace for “open” after you “cut” the trace. THIS IS AN ESSENTIAL step on each trace modified. If you do not verify that you’ve completely severed the trace so that it is “open” you cannot expect the mod to work and you may find yourself having to go back and “re-cut” them (too much work). Once you’ve verified that the trace is properly cut (open – no conductivity), move on…

g) Now, lightly twist the brown and grey wires together (this will aid in avoiding signal interference) and strip (remove) a tiny (1/16th inch) portion from the end of both the brown and grey wires from their ends and “tin” them.

h) Tin each solder point on the trace ends (one end is the tip of a micro surface-mounted capacitor – be careful here not to apply too much heat with the iron).

i) Now carefully solder the brown and grey wires as illustrated in the pix.

j) Retest the trace to ensure it is still open and test for continuity between the DB-9 interface connector (brown is pin 6 and grey is pin 5) and each side of the trace where it is cut (that’s why I scraped away a “test” pad on the trace where it is cut).

If you’ve followed these steps carefully so far and the continuity tests confirm good results, you are ready to move on…


k) Before re-mounting the Display screen to the Display Assembly, you may wish to “cover” the exposed surfaces which were scraped away (when you removed that “blue” material) with a non-conductive coating (I did not). Re-mount the Display screen and replace the Phillips head screws removed earlier. Take care to not pull too hard on the brown and grey sync wires when doing this as you do not want to damage your work and have to go back and fix it later. Once the screws are replaced, re-solder the screen frame tab (you un-soldered this earlier) back to the circuit board where it was originally soldered before (here is where that solder wick used earlier will pay dividends)

[jhelmuth]

[2] Turn the board over now on its face begin repeating these steps (see e-j above) for the remaining 3 signal traces (green/red/blue). I will note below any additional tips and/or tricks as they relate to this part for each signal trace…




Connector CH102 – Note the arrows in the pix where the connector solder leads meet the plate-thru holes – this is where you want to make your cuts. I would make all 3 cuts next, testing them as I go along.



Green/Yellow pair: Be extra careful not to bridge your cut when soldering the yellow wire to the connector lead (also true for the lavender and orange wires as well). You will want to strip some of the surface material off the trace end where you will solder the green wire to allow for a good and easy solder joint. This is the 2nd hardest pair to work with as the space is cramped between the components and the solder points (the blue/lavender and red/orange pairs are relatively easy compare to the other two pairs).



Red/Orange and Blue/Lavender pairs: Solder the orange and lavender connections first, followed by the red and blue wires. This will give you the most “room” to solder without cramping the work area with wires.



[3] Loosen Display screen mounting screw #1 enough to wrap the “bare” signal drain wire (a.k.a. shield wire) around once and re-tighten (leave about 1 inch of slack in the drain wire). Then solder the black wire to a ground point. I choose to use the POT solder connection near Display screen mounting screw #3 (see pix).



This completes the wiring!

1st 2 pix shows the "target" wiring and locations for cuts...

[jhelmuth]

Step 5 – Re-assembly



[1] Reconnect the small black wire from step 3.3 (above).


[2] Making sure that the wire pairs are not in the way, carefully re-attach the Display assembly to the 3 connectors of the Nav unit.
Note: you’ll have to carefully “manage” the TVandNav2Go interface cable back out so that the assembly will not “pinch” the interface cable and/or the interface cable will not prevent the assembly from properly re-connecting.


[3] Replace the 4 phillips pan-head mounting screws from step 3.1 (above).

[4] Carefully replace the front bezel – it should “snap” in place – and replace the 4 top and 8 side bezel screws from steps 2.3 and 2.4 (above)

[5] Replace the Vol and Tune knobs. Make sure they are all the way in – there is no particular orientation here.

[6] Replace the joy-stick knob. This one has an orientation to it. Note the flat part of the shaft where it joins to the “notched” part of the knob, DO NOT force this. If it does not go on without extreme force, it is not oriented correctly. Re-evaluate the orientation and try again.






That should be it! You’re all ready to test the unit and complete the install!

[domoftvandnav2go]

Hi Everyone
If you don't think you can do it yourself, we can do the whole job for you for $450.
Thanks Dominic of www.TVandNav2Go.com

Originally Posted by lennoxavesosa

If I could hug you right now....I would! Thanks a million for the excellent write-up! You sure save me (and a buncha other people Im sure) a lot of time and money!

...Still debating whether or not to do it myself, or have it professionally done. But it will be that much easier to have someone else do it now that I have thorough instructions!

[domoftvandnav2go]

Hi Jim
Excellent write up. Just 1 note you should also ground the shield wire to prevent a ground loop.
Thanks Dominic of www.TVandNav2Go.com

Originally Posted by jhelmuth

Step 5 – Re-assembly



[1] Reconnect the small black wire from step 3.3 (above).


[2] Making sure that the wire pairs are not in the way, carefully re-attach the Display assembly to the 3 connectors of the Nav unit.
Note: you’ll have to carefully “manage” the TVandNav2Go interface cable back out so that the assembly will not “pinch” the interface cable and/or the interface cable will not prevent the assembly from properly re-connecting.


[3] Replace the 4 phillips pan-head mounting screws from step 3.1 (above).

[4] Carefully replace the front bezel – it should “snap” in place – and replace the 4 top and 8 side bezel screws from steps 2.3 and 2.4 (above)

[5] Replace the Vol and Tune knobs. Make sure they are all the way in – there is no particular orientation here.

[6] Replace the joy-stick knob. This one has an orientation to it. Note the flat part of the shaft where it joins to the “notched” part of the knob, DO NOT force this. If it does not go on without extreme force, it is not oriented correctly. Re-evaluate the orientation and try again.






That should be it! You’re all ready to test the unit an complete the install!