So I took apart the BMW Business Radio... DIY sorta?

I have not for the life of me been able to figure out whats wrong with my display, and i got bored one day and took it apart...

that was about 2 years ago.

a couple weeks ago, i got bored again, and decided to once again take it apart, for two reasons.. to fix the volume knob which mysteriously stopped working after my last destruction, and also to investigate the LCD again.

here is what i found.. (FYI, this is the '01 Blaupunkt Business Unit.. not the alpine one with mode btn, or the mp3 playing one)



ok, so.... i took the radio out. not that hard, didn't take pics. just remove it and get your tiny star driver set out, because im going to start with it already in my hands.

i have everything laid out on my living room table.

1) shot-glass of rubbing alcohol / distilled water (50/50)
2) apple cider vinegar (good for removing salty deposits and organic)
3) Star driver set.. T2-T12. you will be using mostly T8
4) needle nose pliers
5) a foot (yes, the foot is required. the teddy bear under the table is not. it is merely a prop/dog toy)

and here we go..

first, lets have a look at the unit, with the top and bottom panels off. these panels are easy to remove. they are not screwed in, they just have tabs that slide into the sides. minimal effort here. IIRC, the top panel comes off easier with the faceplate removed. that does require screw removal.



the CD rack is held in place by 4 screws in the corners, as you can see. remove them, and it lifts out. you can now see this...




the orientation of the unit is Face = bottom of pic, plug = top of pic.



there is the CD unit by itself. there are no wires or ribbon cables attached to it. it merely sits in place and makes connection via a plug on the circuit board.

here is the bottom of the unit. nothing interesting here.


here is the FM tuner. i couldnt manage to find a screw on it, or tabs to remove its panels.. so i didnt get a look inside.



looking straight down, in the center of the pic is the plug for the faceplate ribbon connection. to the left in the shadow is the black plug for the cd unit.


here is the faceplate CB


and the volume control.. it lies on a separate CB and sits at an angle. this situation is why my volume knob no longer works. i lost the piece that connects the two boards. i'll show you later where it goes..



heres where the LCD attaches to the faceplate


the back of it looks like this. there is no electronic connection here. the silver metal is a casing for the LCD.



to remove the LCD, you need to lift these pins/tabs up and it lifts up from the CB. like so... (WARNING: if you remove the LCD, you will likely break it. i wouldnt advise this!!! )


heres the faceplate CB without the LCD. the white boxes are the backlight LEDs for the screen. the long row of thin metal strips is the connectivity for the LCD.



better pic of LCD connection


this is the LCD insides. or rather the orange glow/light diffuser


this is the actual LCD glass. (WARNING: if you remove the rubber strip, you broke it. DO NOT ATTEMPT TO TAKE THIS APART!!!)


this part is why my screen does not work. the rubber does not make the correct contact points and thus, my screen displays un-recognizeable characters and a jumbled mess. i only took it apart because i bought the car like it, and i have never had it working. if yours works.. DON'T TOUCH IT! it's very easy to break.



------ and intermission while i create POST #2 -----------------

This is another shot of the LCD screen, looking at the connectivity side. the right edge is the rubber strip/connection

From BMW Business Radio

here is the faceplate plug/ribbon connection

unlocked

From BMW Business Radio

and locked

From BMW Business Radio

this is the volume knob connection. the 5 gold contacts do not make direct contact with the PCB of the volume knob. they require a middle piece, which i do not have.

From BMW Business Radio

this is how the volume knob goes back together.. bottom to top, left to right

From BMW Business Radio

and finished

From BMW Business Radio

this little weird guy is the holder for the connection center piece

From BMW Business Radio

the piece i am missing sits inside of it.



this corrosion i fixed

From BMW Business Radio

and i stopped there, put it all back together, and live life with volume control on my steering wheel. the knob is just there for looks, until i either find the piece or get a broken radio from someone. in all, i really accomplished nothing, except taking pictures and finding out that i'm a dumb-ass and lost the piece i needed.

so, i hope this killed some of the curiosity some might have of the insides of the Blaupunkt BMW Business Radio.

and the usage for the foot?

walking to my porch to enjoy this..

From July 4th, 2010

lol very cool

EE ftw

The problem with your display is the elastomer, which is the rubbery strip that connects the LCD to the circuit board. It is flexible contact strip that passes power from the circuit board traces to the LCD panel. The need to stay rubbery and the conductive material can degrade or oxidize over time. All the gray colored elastomers tend to go bad over time causing LCD display digits to go faint or not show up. There are some newer pink/orange elastomers that seem to have a better material make up that seem to last longer on other equipment, not sure there is anything like this for the radio??

Just search Fluke 83 display on the web or ebay and you will find folks that have replacement elastomers for the Fluke meters, I have had to repair mine. Some may even explain in more detail what the problem is.

Usually these last about 5-8 years, then fade, but in a car with the temps they could fail earlier.

The question is does anyone sell replacement elastomers for the radio?? If they did, they would only be around $25 would be my guess.

Sometimes cleaning the elastomer with alcohol may help, but the will usually fade or quit shortly there after.

Originally Posted by jfoj

The problem with your display is the elastomer, which is the rubbery strip that connects the LCD to the circuit board. It is flexible contact strip that passes power from the circuit board traces to the LCD panel. The need to stay rubbery and the conductive material can degrade or oxidize over time. All the gray colored elastomers tend to go bad over time causing LCD display digits to go faint or not show up. There are some newer pink/orange elastomers that seem to have a better material make up that seem to last longer on other equipment, not sure there is anything like this for the radio??

Just search Fluke 83 display on the web or ebay and you will find folks that have replacement elastomers for the Fluke meters, I have had to repair mine. Some may even explain in more detail what the problem is.

Usually these last about 5-8 years, then fade, but in a car with the temps they could fail earlier.

The question is does anyone sell replacement elastomers for the radio?? If they did, they would only be around $25 would be my guess.

Sometimes cleaning the elastomer with alcohol may help, but the will usually fade or quit shortly there after.

holy crap! you are the first person that has ever know whats wrong with this thing..

so, i did a little searching and found Elastomeric connectors.

and this on ebay.. http://cgi.ebay.com/MULTIPLE-CONTACT...item335da38194

i dont knwo how these things work, but that looks damn close to the blaupunkt one used.. $7 shipped isnt a bad price.. think it would work?

Here is the deal, the little black items sandwiched inside the gray rubber are connection points. I am not sure what the makeup of the black material is, however, it need to be conductive.

The issues you are up against is the spacing of the black items, they need to match up with the spacing of your display, they likely will as many LCD displays and circuit boards use a common spacing. Additionally the overall thickness/length of the elastomer is also critical as you need a certain amount of pressure to make the contact between the LCD and the circuit board, but no enough to cause the LCD to break when you snap the LCD bezel back on. Usually there is a channel or groove the elastomer sits in to align it to the circuit board and LCD panel and the width of the elastomer needs to be close and fit in the channel.

You need to be careful not to get oil from your fingers on the LCD and the elastomer. Usually you can take a old/spare elastomer end to use is an an eraser to clean the contacts on the circuit board and on the edge of the LCD to clean off any of the old elastomer that actually stuck to the circuit board or LCD. Usually the elastomer is a single use item, but look at it this way, if your radio display is flaky and you think the LCD is fine, then for $7, you either win and get it working or loose $7. Kind of like playing Lotto??

If it works you can celebrate with a few beers, if it does not work or if the elastomers are the wrong size, you can numb the pain and sorrow with some more beer!

You will only be out $7, so you may have to buy some cheap beer for the week!!

Good luck, hopefully you will get the display working?? Otherwise time for a parts radio or an upgrade?

noted, i think i'm gonna buy it this weekend and try it out. $7 isnt much of a loss. gonna bust out the magnifying glass too to line this **** up. i figured that was important, just as you said.
each contact on the elastomer is a column on the LCD, right?

Yup, each dark section in the elastomer is a connection point. Many devices that have the elastomer have some sort of plastic shroud that aligns the elastomer up with the circuit board and the LCD display. This shroud keeps the elastomer at a 90 degree angle to the circuit board and LCD as well as align the elastomer with the connections on the circuit board and the LCD panel.

Not sure if you are missing this shroud or if you have and it just not pictured.

The connections are pressure connections and the elastomer can actually stick to the circuit board and LCD over time.

I admire both your persistence and attention to detail (though perhaps not the too much beer during the job causing you to lose essential parts).

I like it when someone takes the time to take things apart to try and fix them and posts pics for us to see.

If the repair doesn't work though I'd be tempted to source a later model from ebay with the mp3 input and turn your attention to wiring the mp3 input into your car.
(By coincidence I contributed a detailed post to that thread about how to do just that)

http://forum.e46fanatics.com/showthread.php?t=422239

devious, question, did your display fade out, or did it look like mine?
http://forum.e46fanatics.com/showthr...272&highlight=

ohh... crap! maybe i can fix my trip odometer. when i messed with lcd in my instrument cluster, i chipped the bottom layer of the glass ever so slightly... the rubber strip makes contact everywhere else, except where i chipped it, which is (thankfully) just some numbers in the trip odometer. i can only see the digit after the decimal point now. maybe i don't have to buy a whole new cluster to fix it

thanks guys. most informative thread i have read today.

I wanted to take mine apart, but I can not find a screwdriver that fits the screws holding the front panel to the control panel. Would you kindly post here or email me at hmilani3@optonline.net what is the screwdriver head you used. Thanks.

I wanted to take mine apart, but I can not find a screwdriver that fits the screws holding the front panel to the control panel. Would you kindly post here or email me at hmilani3@optonline.net what is the screwdriver head you used. Thanks.

So you only have one foot?