revtor

Can you tell me how you have done this?The problem is that my approach works for the E31 but not for the E30. I don't think the E30 has a light sensor to adjust the brightness of displays in the car (correct me if I am wrong) and the instrument lights dimmer is (electrically) extremely inconveniently placed between lamps and ground instead of positive terminal and lamps like in all later bimmers. The instrument lights signal is available at pin 13 of the 16-pin BMW radio harness connector (old style with round pins) and the BMW-to-ISO adapter should carry it pin 6 of the ISO A socket on the back of the Becker headunit from where you could use it, but in the E30 the voltage will always be the battery voltage - regardless of the dimmer. In the E31 the dimmed voltage is present at that pin. You will need considerable changes to the Becker headunit if you want its button illumination to follow the E30 dimmer. If the E30 has a light sensor to adjust the brightness of the odometer display I couldn't find its signal outside the instrument cluster in the E30 electrical diagrams. In the E31, the display brightness signal is available as a pulse-width modulated (PWM) signal between instrument cluster and multi-information display (MID) (although not in the radio harness but that's just a single wire to run). Anyway, perhaps you just want to increase the brightness of the buttons - regardless of the dimmer or even the instrument lights - and leave the display as is? Still not an easy task because both display backlight and buttons have the same power source. For the [ON], [EJECT] and both rotary knobs this is not that hard because you can simply intercept the wires to them and connect them to another power source, but for the buttons on the removable front this an entirely different story. A new power source must be led to the front, but as far as I know there are no contact pads left unused and since the front is supposed to be removable you can't simply run new wires to it... For my own modifications I had to separate the display backlight and button illumination as well and I found a solution by using the metal spring hinges that hold the removable front. I (ab)used these as extra contacts. A new trace runs on the display PCB to the side of the PCB where the hinge cavity of the enclosure is. The trace ends in the cavity so it makes contact with the metal spring hinges of the base unit when installed. I wish I had pictures to make it more clear, but I don't have any - sorry. Meines Wissens ist dies von der Firmware gesteuert. That's the funny thing... The subwoofer is actually present in the BMW firmware: You can adjust the subwoofer volume in the [sOUND] menu, but the output always remains silent... First I thought I had a bad BMW Indianapolis, but when I followed the traces of the subwoofer output on the printed circuit board (PCB), I noticed the actual hardware was not installed in the BMW version. The traces and islands are there, just the same as in the genuine Becker Indianapolis, but there are no components soldered onto the PCB (pre-amplifier IC, capacitors,...). Not sure why BMW asked Becker to drop the subwoofer output from the PCB, but it probably has something to do with cost. Since the subwoofer option is still present in the firmware, I am quite sure the output can be revived by soldering the missing components in place, but that means you would need a genuine Becker Indianapolis to source the components from and professional desoldering/soldering equipment because it's all extremely small surface mount technology (SMT)... Anyway, it's not that much of a loss. Most subwoofer amplifiers also accept a plain stereo input. You only lose the ability to adjust the subwoofer volume on the head unit independently from the main volume. Could you please ask him where in the firmware the Becker and/or BMW startup logo is stored and in what data format? Would it be possible to reflash the firmware (and logo) through a modified navigation cd?

This may sound stupid, but I don't really have good close-up pictures of the finished PCB. Laying traces and especially positioning the LEDs wasn't exactly a pleasant job, so I when I was close to completion of the modification I was so eager to see it working I didn't really bother taking good pictures. Dumb... :( Anyway, here's a higher resolution version of one of the pictures and a quick and dirty drawing I just made that should hopefully clarify how I relocated the top row contact pads. http://tweakers.net/ext/f/8hQEYL7BmvfdytfRYR9xF8eN/medium.jpg Larger view http://tweakers.net/ext/f/SnHsTf6KyqIY9mXZj1HuIDBf/medium.jpg Larger view Refer to the first picture for the orientation of the LEDs as they are not always mounted with the cathodes facing each other as in the drawing. The "TP" contact pad was relocated exactly like the other contact pads. Obviously the lengths differ, but the principle I used is always the same as shown in the drawing. The problem with the "TP" button is that there are a few components where the relocated contact pad should come. Since the components are only low profile SMT resistors, I simply glued the plastic insulation foil right over them. That meant the "TP" contact pad sits higher than the rest. In fact, it was so high the "TP" button was triggered by the slightest contact. I fixed that by carefully reshaping the backside of the plastic "TP" button.

electronix: Congratulations! I found this topic when I stumbled upon pictures of an Indianapolis with inverted display other than my own. Now there are at least three Indianapolis head units on this planet with proper BMW negative display. I know of someone in the UK who performed a polarizer filter swap like I did in my first version of the modification - actually around the same time and without knowing about each other's attempts - but also with mixed results. As far as I know you are the only one so far who repeated my second version of the modification . In the meantime I have modified my Indianapolis even further. I replaced the BMW Indianapolis 7969 base unit with a Becker Indianapolis Pro 795x. The only major change between the Indianapolis and Indianapolis Pro is the addition of bluetooth in the latter, but the bluetooth telephone implementation is rather primitive. Definitely not worth the upgrade. In fact, I like the antique factory BMW handsfree GSM much better. The real reason for choosing the genuine Becker version over the BMW version are hardware changes Becker made for BMW. The BMW Indianapolis does not have a subwoofer line-output. The subwoofer settings are available in the software, but the output pre-amp is simply absent on the PCB (the traces and islands are there, but the actual components are missing). The BMW version has a different cd changer interface to make it compatible with the BMW I-Bus. I-Bus compatibility allows control of the head unit with the multifunction steering wheel buttons and the use of BMW cd changers, but the BMW version is not compatible with the Becker Remote Kit (iPod interface). Since the E31 8 Series was never available with multifunction steering wheel and I don't care about the cd changer, I chose the Becker version to be able to use an iPod. I didn't care about bluetooth, so I could have gone with a regular Becker Indianapolis 792x just as well, but I got an interesting offer for a brand new Becker Indianapolis Pro 795x (keep in mind the genuine Becker Indianapolis head units will not work with BMW multifunction steering wheels, nor BMW cd changers). The only sad thing about using a genuine Becker version instead of the BMW version is that you loose the "BMW" text logo when the head unit is turned on. It's now showing the Becker logo. The startup logo is in the head unit's firmware. Maybe I'll try to change the start-up logo in the future, but right now I'm happy with the head unit as-is. http://tweakers.net/ext/f/ghOwUypCgsPod2Ud0BPvM0j3/full.jpg iPod attached through Becker Remote Kit. Also note the telephone logo left from the TP and TMC indicators on the display. This indicates a bluetooth connected telephone. I also separated the display backlight from the button illumination. The button illumination is now adjusted to and controlled directly by the car's instrument lights dimmer. the display backlight is now controlled by the instrument cluster's ambient light sensor. When it's dark, all displays in the car dim in order not to distract the driver - including the head unit. When it's bright, all display go to maximum brightness to ensure maximum visibility. Really nice. I didn't document these changes, though. I never thought someone would actually perform the modification as well... http://tweakers.net/ext/f/QNYyqyGPUBBKxAe1TWMyP2J5/full.jpg During daylight: Bright display and no button illumination. http://tweakers.net/ext/f/YzAest1l2fFPKG4PWodFEvMe/full.jpg During nighttime: The headlights and thus also instrument lights are now on - the head unit follows (if the head unit is turned off, only the "ON" button is illuminated). The picture cannot really capture it, but in the dark the ambient light sensor in the instrument cluster dims all displays, including that of the Becker. In other words, the Becker display always matches the brightness of the other displays in the car.