Originally Posted by Terry Kennedy

The reason the part number doesn't show up there is because they're using a 15-month out-of-date catalog (the opening banner says "New Updated 2/09 Catalog").

Penske operates a BMW-sanctioned web catalog here, though you don't want to buy from them (at least not at those prices, which are US list).

Tischer has an online catalog here which offers discounts.

The final arbiter of what is and isn't a valid part is the live BMW ETK. Here is a 3-page snapshot from the live system as of this morning.

Looks like the list price is $100 with a core charge of $500. Which is borne out by the description of the part in the BMWNA ordering system (not the ETK): "EXCHANGE DVD DRIVE ASSEMBLY". At the moment, the 65839232059 drive (non-exchange) is still available for $817.09. But if you look on page 3 of the PDF I linked above, that part has been superseded by the 65839237706 as of March 29, 2010 so inventory will not be replenished.

Originally Posted by Roy in GA

The parts screen is supposed to be 65_1650. I could not find the screen though. The parts info page said the old P/N was 65 83 9 232 059 and was interchangeable with the 706 part. The Tischer price for the new is about $80 and the old abou 650. I don't understand this.

Originally Posted by Roy in GA

Terry, thanks for the info. I couldn't open the PDF though as my computer said the file was damaged. Does it have an SI number?

Originally Posted by Didi

This is a DIY for changing the laser unit in a MK4 sat nav unit.

If the MK4 has problems reading map DVDs (regardless whether it is an original or a burned copy) the problem of repair arises.

In fact you have several possibilities:
a) Buy a new computer from your BMW dealer: no option for me. Much too dear.
b) Buy a new computer at ebay: no option for me. Too dear as well.
c) Send the computer to the VDO repair centre in Germany (here): I tried to reach someone there without any success.
d) Buy a complete DVD unit (addresses at the end) and exchange it: there must be a cheaper possibility….
e) Change the laser unit (addresses at the end) of the DVD unit: that’s it!!!!!

First of all: I don’t take any responsibilities. Everybody should know what he think is able to do.

Keep your hands off if you are not used to handle with a small soldering iron and the below mentioned tools!!!

Tools needed: small soldering iron, desoldering braid, screwdrivers Torx T4 to T8, small screwdriver for slotted screws.

To open the MK4 you cut he seal at the back and remove the top cover carefully.
It should look like here:


The drive is screwed with 4 Torx screws (red circles). Unscrew them.
The drive is connected with 2 cables. One of them simply is plugged in (red connector) and can be released by pulling. The second cable is a ribbon cable.To release it you first have to move the locking mechanism on both sides carefully with a small screwdriver towards the cable as shown here:


After that the ribbon cable may be pulled out.
We will have to open some other of these cables during our repair process. The way of doing it is always the same.
The sat nat computer has lost its drive now.


You have the complete DVD drive in you hand.


For those of you who bought a complete DVD drive you just have to reassemble everything with the new drive in reversed order.
For all others: now it’s going to become interesting.
On the top of the drive you see a shielding plate which is soldered at its four corners.


Open the 4 solder points with the desoldering braid or a suction pump. After that you may remove the shielding plate carefully.
Now it should look like here:


The red circles show the former solder points of the shielding plate.
Next you have to open the two connectors (yellow circles). After that remove the ribbon cable of the laser unit (orange circle) as described above.
Now you have to unscrew the tree Torx screws (green circles). The printed circuit board (PCB) is just plugged in on its right side (on the photo).
It should be flapped to the right side. Now it should look like here:


Remove the two ribbon cables (red rectangles).
Now it should look like here:


On the laser unit you can see a small metal shield. It’s screwed with a small Torx screw and a very small crosshead screw (red circles). Remove both screws.

The metal shield connects the laser unit with the spindle drive with shaft joint (green circle). In addition the metal shield actuates the end switch (yellow circle).

Now you may move the laser unit on its rails. It should look like here:


Next you have to remove the two T4 screws (red circles) that secures the rails at there far ends.
The laser unit can be removed now by sliding it out carefully.

The new laser unit may be assembled in reversed order. While doing so keep an eye on the small end switch at the motor. It has to be actuated by the metal shield.
The laser unit should slide easy and smooth on its rails. After that:continue reassembling.

Important; don’t forget:
Before assembling and soldering the shielding plate you have to remove the two small solder bridges on the ribbon cable (red circles). See here:


And now have fun with your functioning MK4 computer!!!!!

Where to buy:
The DVD drive may be bought as a complete unit. It’s called "DVD-M3-4.6" and it costs about 130 euros.
I found the following distributors (most of them in Germany):
http://www.navigatie-onderdelen.nl/Webwinkel-Product-285814/DVD-M3-4.6-(navigatie)-loopwerk.html
N-tronics Lasers: pickups CD DVD (optical units lens lasereinheit www.optical.com www.laser.com VAM CDM cd dvd vcd mp3 optiques lasser lassery spindle) (oa. Aiwa, Philips, Daewoo, Goldstar, Grundig, Hitachi, Philco, Saba, Sanyo, Schneider, Sony, Kenw
Audio-Ersatzteil DVDM34.6 (DVD M3 4.6) - 930700630401 BMW NAVI MK4/MK-IV...
DVD M3 4.6 - LASER MECH WITH SFHD4/B - Powercomponents
http://www.ebay.de (search for: DVD-M34.6), seller: bully1313
Laufwerke fr BMW CD/DVD-Navigationssysteme bei Lesefehleren
Grandata Online

The laser unit itself is called „SF-HD4“.
You may buy it
- at ebay (search for seller „spillomax“) about 40 euros plus postage and packing
- as remaining stock at Pollin (were I ordered) for 4.95 euros plus postage and packing

Acknowledgment:
I’d like to thank „Paceyon“ from the German Motor-Talk forums who posted a verbal description first.