mkiii nav blank screen radio ok
 

My symptoms - blank nav screen but radio, cd working fine all buttons both sides operational. The nav screen was working fine. (went off during a journey actually). I have updated the screen from 4:3 to 16:9 but was still using the original mkii nav unit. This set-up has worked fine for several months until now.

Things I have tried - shutting down and removing from power overnight, powering back up and re-installing with older os (v17.1, v18). Nothing.

My thoughts: Does the nav computer need to have the original screen when re-loading software? Or does this point to the screen being faulty? Or is it the nav drive dead?

Any ideas?

Update - swapped to 4:3 screen up front to test - still the same - black screen

Have tried endless nav software updates (different versions V17, V18, V24, V25) red led on and off as disc gets read but still nothing happens on screen.

Last time this happened I did get the os to reload and saw the screen updating but not this time.

Do i conclude the nav computer needs changing then? Or does anyone know of how to test/repair the computer.

Help appreciated.

That sounds like a dead nav computer. If you have a blank screen, then you have one of two problems: either the screen is dead or the nav computer is dead. Since you have the luxury of a spare screen to test, you most likely eliminated the screen as the problem. Therefore, the problem is the nav computer.

Update - managed to get replacement mkiii computer (used) and still the same - no picture.

now what? any one know what to check?

bm receive rgb signals from mk, so if the replacement mk is ok, maybe you have problems with cable loom or bm, better use a diag sw like inpa or dis to diagnose all parts involved, also check fuses...maybe you are lucky :)

does the cd/dvd drive have power?

is completly blank or no backlight? can you see it in the day time?

Sorry I didn't mean to hi-jack this thread so I moved to a new post: http://www.xoutpost.com/electronics/...nk-screen.html

The screen is blank nothing displayed at all, but the screen does energise just shows a light shade of black/grey from what its like in the powered off mode.

No probs Alan Z - same issues i think


Update

My situation - screen working but how and why is still mystery

What I did was... i took out fuses 71, 72 and the two green relay blocks from rear trunk and checked before replacing - no change still blank

as i drove away it suddenly displayed everything on the bordmonitor except the sat nav (in a old style blue screen format which i believe was the TV module taking over)

I tried to update the software thinking that i could at least see if the os was loading - no change still old blue screen

so i decided to put the original nav unit in and hey presto saw the bmw logo and then normal screen nav included

i havent got a clue how and why - maybe someone else may be able to shed light but it could be worth doing the fuse check?