Problem with LCD display

[twhitestone]

Hi,

I have been trying to solve a problem with the LCD display at the bottom of the instrument cluster on my 1988 BMW 735i - the whole "unit" does not display information. It lights up dimly because I replaced the lightbulbs behind it. I am referring to what I believe is called the "check control" display, spanning from the left odometer, across the message center and service indicators, to the right side where the gear and transmission mode indicators are located. Just tonight I replaced the capacitors on the circuit board inside the instrument cluster, as that seems to be a culprit for these types of problems. That didn't change anything. Now I am thinking that I might have to replace the Check Condtrol Module (in the engine compartment fuse box) or the LCD panel (in the instrument cluster) - is there any way to know which one is likely to be causing the problem? Is there something else I am overlooking?

Tom

[twhitestone]

It was the capacitors after all! I had replaced the three "lower" caps, but not the two in the top row above them! It works! I am so happy!!! Now to fix all the warnings that the check control is reporting...

[1988735iLBrooklyn]

Junk Yards / Refurbished sells the Intrument panel assembly the whole assembly for less than $100.00 but the labor you need to remove the steering wheel.

good luck
Part Number for my 1988 735IL Instrument Cluster panel assemly is
VDO 12V K=7295

110/008/389/040

1 388 083 9

Made in Germany

[750iL96erbill]

Tom,

I realize you sent this over a year ago, but I was wondering,
can you tell me more about the cap replacement? Was it a pain, is it still good today? Is that the issue with these things, bad caps?

Thanks, Bill

[twhitestone]

Hi Bill,

Yes, it still works fine. It took some patience but I was able to do it without hurting anything - and I had relatively no experience with circuitry or soldering.

Tom

[750iL96erbill]

Originally Posted by twhitestone

Hi Bill,

Yes, it still works fine. It took some patience but I was able to do it without hurting anything - and I had relatively no experience with circuitry or soldering.

Tom

Hi Tom,

Wow that was fast, Thank you so much for replying!

Can you give me a little help on doing this? My son and I both have this problem and he even bought one off ebay with the same, so we have one to experiment with. Where did you get the caps? It takes five, right? Do you remember the size. I do not have much experience with this type of thing, but wife was a solder person for Maxon for awhile, so will employ her support!!
Thanks again.
Bill

[750iL96erbill]

Hi Tom,

I hate to be a pain, I have opened up the box and now I am down to removing the needles on the gauges. Can you tell me, do they just pop off?
Thanks, Bill

[blkchef92]

Hello i just got a 89 735 I with the same problem can you guys help me out with this?