I tried tapping pin 5 to an RCA cable that i connected to the Y terminal of two different tv's component inputs... no image.

You said YUV, these terminals both read Y (Green), Pb (Blue), Pr (Red).

I don't think either is multi-system.

I still have not yet proven that:

a) boardmonitor is bad
b) gps units are good

I need to find someone who will let me test at least my gps units in their car. I am thinking I might just crack the monitor open and take a look. I would really like to prove one way or another that the monitor itself is bad before sending it off to Alpine.

I just took the metal top cover off the monitor unit. Right away I notice the two ribbon cables are off their little plastic holding pegs. Though they still seem to be solidly connected to the two white plastic input receptor things.

I'll try removing them, swabbing with some alcohol and then reseating the cables.

Question: does this need to be done on the screen side as well?

Thanks!

I doubt it.

Whe the monitor is originally delivered, the screen and body are supplied separately.

The installer must assemble the two, and connect the ribbon cable

Thus the ribbon cable in the main unit would have been touched be human hands, but the cable in the screen would never have been touched and should still be good.

Well I just reseated them and I still have the same white screen. I am guessing the unit is defective in some other way.

Just wondering if it's worthwhile dissamebling the main screen and inspecting the PCB perhaps reseating that cable (if that's even possible).

Looks like it's going to cost $350.00 to get it fixed :(

Sorry again for the long post and multiple questions:

I tried once more, and even tried having only one ribbon cable or the other connected. Looks the slightly thinner (26 pin) one on top supplies the video. When I disconnect that the screen is completely blank. Disconnecting the bottom one seems to render the controls useless so I am guessing that is the ibus one.

I'm still not convinced the monitor is dead. I wish I had another way to bench test the unit. No one is going to let me test it in their car, I'll be lucky if someone will even let me plug my GPS units in.

Is it worth it to try and run three taps for RGB from the GPS harness connector to the monitor harness? In WDS "RGB Signals (Without VID Video module)" gives the pin mappings from the 18-pin GPS blue harness connector to 12-pin monitor blue harness connector I am just at a loss for how I can test this without having another car w/NAV available.

Are the wires that originate from the GPS side the same color if they terminate on the monitor side? This is what I was trying to prove with my multimeter and was getting strange voltage readings with the car battery disconnected and looping a 1.5V AAA battery across various pins (i.e. I was getting >1.5V readings on pins that should NOT have been getting supplied any voltage).

One last thing. If you pull the GPS unit - should the screen go blank or should it be white? Is there ANYWAY to test the harness out with just a multimeter or is this only possible with a oscilloscope? I just want to test for continuity I would think since I have 2 GPS units and the likelihood of both being bad is very small.

Lastly either I am assuming I did something wrong trying to tap the green channel to the Y input of my TV's or they are not multi-system (or was that just required for regular RCA video input?)

And this cable inside the screen housing is what you are saying is NOT worth reseating, it looks like it is clamped down pretty well anyway. I don't see any point in dissambling the screen portion if it won't do me any good either - though I have heard of some resistor or other component "melting" in here. Apparently from doing a little searching it should be fairly obvious is this is the case.

Will any oscilloscope suffice? I was looking at some local ones on craigslist, most of which are ancient and huge as well as some USB based ones like these:

Link 0
Link 1
Link 2

If you want to ship the screen and nav drive to me in Michigan, I'll slap them individually into my X5 and see if they work or not. It'll take me all of 5 minutes to prove it out one way or another. And the shipping back and forth would be a lot cheaper than buying a scope.

Did you try swapping just the monitor with the MK2?
As UCrewX5 suggested its very quick and simple to test on another X5 with nav, if you can find someone.

thats the problem i cant find anyone. If i could i would test both my gps units. Hard to beleive no one in PHX metro will step forward....

Ask around on Bimmerboard.com as well for any E39/E39 owners in your part of the world to help you.

Honestly, the quickest easiest way to test is to fit the units in a known working vehicle.

If you are not familiar with oscilloscopes and the correct waveforms for video signals then you will struggle to understand what you are seeing, and you will struggle to drive the oscilloscope

Keep hunting for a friendly BMW forum member within your town or within a couple of hours drive from your town.