Is whole MK IV fried or is it just a dead drive?

bmwnavnewbie · #1 07-02-2009, 01:19 AM

My nav quit working yesterday (coincidentally while car was on Deltran Battery Tender Jr.) and I got the typical black screen with occasional horizontal white flashes. Couldn't get the DVD out, and the DVD drive acted differently than it ever has - usually when it can't read a disk the power light stays on and it keeps trying for awhile, and it tries to read the disk when the trunk is opened. It was giving up much more quickly this time. I opened up the unit, lifted the motor, and got the disk out thanks to the nice instructions at

http://www.xoutpost.com/articles/all...ion-drive.html

Reconnected the unit (with no disk in it) and still get the flashing nav screen. Normally with nothing in it, it should say "No CD/DVD". So I'm wondering if it's likely that the electronics that are not on the DVD M3-4.6 drive module are dead, or if there's a good chance that the DVD M3-4.6 replacement will cure the problem.

Anybody have similar experience and/or have an opinion whether a drive replacement will fix it (obviously that would be the least expensive solution)? Any chance the battery tender connected in the engine compartment would have affected the DVD player in the trunk (should be some voltage drop from front to back)? Doesn't seem like the battery tender voltage is any higher than alternator voltage.

Thanks very much for the help.

Sponsored Links

KiwiJochen · #2 07-02-2009, 02:10 AM

Sounds very odd.

First thing to do is a battery disconnect: disconnect battery, wait 15min, then reconnect. This resets everything in the car.

Second thing: Do you have a TV tuner fitted? if so, unplug the nav and let the TV take over generating the picture to ensure the rest of the system is OK.

But it may be that the nav unit has failled. You could try sending it to VDO in Wetzlar Germany for repair.

bmwnavnewbie · #3 07-02-2009, 02:23 AM

Quote:

Originally Posted by KiwiJochen

Sounds very odd.

First thing to do is a battery disconnect: disconnect battery, wait 15min, then reconnect. This resets everything in the car.

Second thing: Do you have a TV tuner fitted? if so, unplug the nav and let the TV take over generating the picture to ensure the rest of the system is OK.

But it may be that the nav unit has failled. You could try sending it to VDO in Wetzlar Germany for repair.

Yes it is odd, at least compared to how the drive acts when it's not reading the disk properly.

I disconnected the battery a couple of times, for several minutes, with the same results each time. But I'll try again and leave it disconnected for an hour or more. EDIT - disconnected battery for several hours, but that didn't affect the situation.

No TV tuner or anything else is installed. It's totally stock electronics.

Sounds like you agree that it may not be the drive. I'll probably get one anyway, as a gamble that it will fix the problem. Then at least I can reuse it if I have to buy a used full replacement unit.

Thanks.

autotronic · #4 07-03-2009, 10:13 PM

Hello from downunder,

I follow your posts with great interest and although I don't own a BMW, I'm presented with the problems such as these from various sources. The "dead" mk3 and mk4 cases (usually coming from battery disconnects) is most unusual for an automotive grade item.

To cut a long story short, I have been able to "reflash" and bring back to life GPS computers that are pronounced dead, because no amount of OS CD swaping as worked.

So far the method has worked on Mk3 and Mk4.

It's very complex to undertake and requires specialised equipment.

Question is how can I help those with such problems from where I am?

KiwiJochen · #5 07-05-2009, 02:50 PM

Can you provide an overview of your method?
(I'm an electronics engineer and have retrofitted and installed many Mk3s and Mk4s)

autotronic · #6 07-07-2009, 07:50 AM

Ok, this might get very technical, but only the very knowledgeable will understand.
Next to the BGA MCU are 2x64Mb Fujitsu TSOP48 bottom boot block Flash. Memory dumps on dead mk3 navis show corrupted (containing mostly 00h) sectors, checksums are vastly off. The entire 32k "protected" boot block is stuffed. This is why the OS CD does not load. Reimage the onboard Flash to fire up the unit. It's not possible to do this by the user interface CD. I leave it to your imagination how this can be done.

KiwiJochen · #7 07-07-2009, 11:22 AM

Perfect, I understand exactly what you're saying.

So you'd connect the TSOP48 adapter, and reload the flash from a file that you took from a good unit. SOP :-)

I've done the same thing on BMW radios when their flash memory failled.

bmwnavnewbie · #8 07-08-2009, 03:35 PM

This is interesting - as you say it's not very good if the boot flash can get corrupted in an auto application. Now for the naive question: Is this flash a plug in chip? i.e., to reflash it do you pull it from the board and put it into the flash programmer? Is the boot code readily available?

I suspect this isn't my problem because I could occasionally get the boot screen and the OBC menus to come up, but no map.

Thanks.

KiwiJochen · #9 07-08-2009, 04:08 PM

It's a TSOP48 package.

TSOP48 = SMD, soldered chip. Google for pictures.

Bootcode can be copied from a working unit.

autotronic · #10 07-08-2009, 07:49 PM

Its a simple test to see whether the Flash is corrupted:

Navi computer LED Power indicator is on = Flash is in good health/system recoverable.
Navi computer LED Power indicator is off = Flash corrupted.

Sponsored Links