1999 E320 dash pixels - PeachParts Mercedes-Benz Forum

rjk · #1 05-27-2013, 06:01 PM

The common fading pixel disease has struck my ride. Has anyone been able to source repair items? I see ribbon cables on ebay but no LCDs. Was there ever a recall for this?

mbdoc · #2 05-28-2013, 08:07 AM

Not a recall, issue is in the connection at the display.

alabbasi · #3 05-28-2013, 08:16 AM

I just bought a replacement cluster on ebay with close enough mileage to my car in order to address this problem. I called a couple of places and they were wanting to charge 2-3 times the cost of a used cluster to fix it. I also had a problem where my fuel gauge was always reading full which would have been something else to fix.

rjk · #4 05-30-2013, 10:59 AM

mbdoc, if I follow the fix outlined over at benzWorld where inserting a strip of plastic/foam in the connector hold-down to increase pressure on the contacts, that should do it? Of course I will clean the snot out of the contacts as well while I have it out.

Edmund · #5 05-30-2013, 07:08 PM

I repaired mine at the end of last year with these:

Ribbon Cable Set for Mercedes Instrument Cluster Pixel Repair W210 W202 W208 | eBay

You get 2 types of ribbons, those with glue and those without. The ones with glue needs to be heated for installation. I opted for the glue option as I didnt want to ever redo this. Its also very important to scratch off any dirt/old glue from the contacts using a credit card edge. The seller instructions explained this nicely with pictures.

You will supposedly need a special tool to install them. I contacted the seller for installation instructions and they promptly sent it through. It arrived nicely packaged and on schedule from the US to South Africa.

I made the mistake of ordering the special tool from china at half the price from equipmentsfinder and it never arrived, so rather buy from the same guys that sell the ribbons. I installed mine by taping it in place and covered it with a thin cloth and then used a normal laundry iron to heat the glue through the cloth. It has worked perfectly ever since.

Most of those connectors are glued to the PCB so removing them for cleaning will do more damage. I picked up a few displays from a scrapyard for spares once and experimented on them and the only proper, lasting solution was the one I described above. If you have never taken the cluster apart my descriptions might not make sense but read them anyway before you start. They will become clear once you encounter what I explained.

A few things to note when doing this repair:

0) Excuse my number, I added this point last. In the left and right hand corners of the display are the high beam, engine warning, etc indicators. This consists of bulbs mounted on the pcb with a triangular plastic strip that slides into the front part of the enclosure. When you remove the front enclosure they will fall out so just keep them safe and install them again just before finally clipping the front part of the enclosure back after the repair. Take not of the small plastic guide pin that fits through the indicator strip. I see some of my scrapyard displays have this strip superglued in which made assembly easier, just be careful as too much superglue will make it look like crap.

1) Be careful when taking the cluster apart as there are many sensitive components, especially the clips on the black and white plastic mouldings. There are nice videos on youtube on how to take them apart. Removing the needles are impossible unless you know the secret...see point 2.

2) To remove the needles, do and understand the following:
The needle moves freely in the range of the stepper motor that drives it. If you encounter resistance while turning it you are turning the needle assy on the axle of the motor. The motor will still function in the correct range but the needle will point to the incorrect place. This is handy for installation and removal of the needles as you will see in the next points.

3)To remove a needle turn it Anti-clockwise until you reach the point of resistance, this should be around the 'zero' mark of the stepper motor. Continue turning it ACW past this point of resistance and pull it lightly upwards. They will come off easily this way. The rest of the assy comes apart by removing clips from the rear. Dont solder out the the stepper motors as some forums suggest, you are just making the display unreliable. See point 5 for installation of the needles.

4)You will have to remove the LCD's to attach their ribbons. Be very careful when re-assembling the the black plastic around the LCD's. Theres 3 of them that is covered by one piece of plastic so installing the last 2 in their seats might move the first one slightly. Clipping back the black plastic with one LCD slightly out of alignment will cause very small cracks through it severing the electrical paths on the glass. Theres no fix for that...I cut the links between the three fittings making installation very easy and I only had to keep one LCD's alignment in mind when fitting the black covers. Each of them still had 4 clips so they fit nicely even without the links.

5)To re-install the needles simply push it back onto the stepper motor axle, dont worry about where it points. I will refer mostly to the speedo needle for easy reference but the method is the same for all needles. Turn the needle clockwise past the point of resistance until it reaches the pin that stops the needle. Turn it back ACW and you will notice it reaches a point of resistance that is way above zero. This is the point that it will now show when it wants to show zero, for example at 0kmph it will show 40 kmph. All you do now is turn it ACW over the resistance to zero. Turning the needle now over the marked range will be very smooth and easy and you will encounter point of resistance at 0 and the other , turning CW at about 300kmph which is outside the marked range anyway(and your top speed). Set all needles using this method. Be gentle and play around with how they move, you will quickly realise how they work and whats needed to set them.

6)To check the accuracy of the needles re-assemble the cluster but dont fit the front part of the enclosure, the tacho step will only apply if you have a digital aircon interface. Connect the cluster to the car in such a way that you can see the gauges and that it wont slip,fall and damage the needles. Scroll through the onboard computer menus until you reach the one that displays the amount of fuel left. I think these cars all have 80L fuel tanks(check your owners manual) so 40L should have the needle at 1/2. If its wrong then REMOVE THE KEY and disconnect the display, set it and test again. NEVER ADJUST THE NEEDLE WITH THE DISPLAY CONNECTED, YOU ARE FIGHTING THE STEPPER MOTORS AND MIGHT DAMAGE THEM! I didnt spend much time setting the water temp as the temp needs to be higher than 40C but you can do it accurately be referring to 7. I will explain setting the tacho, speedo and water temp in 7 as this point is getting too long...

7)With the speedo and tacho needles adjusted to where you think zero is(step 5) connect the cluster as in 6 with the front cover still removed. Start the vehicle. Access the diagnostic menu by holding down the rest button on the aircon interface. You will see the display change showing a number on the left and another on the right. The number on the left is an item number and the one on the right the value it reads. Use the auto buttons to scroll through until you reach item 21(number on the left), this is your engine speed in RPM. See how far the needle is out, switch off the vehicle disconnect the cluster and adjust the needle. Once this is done use the auto buttons to scroll to item 22, this is the vehicle speed. You will have to take it for a drive to see how the digital readout compares to the needle. This can also be done using the menus on the display in stead of the menu on the aircon. I think the readout on the aircon display will always be in kmph so if you have a mph gauge rather use the digital speed display on the cluster menu.

Its not a difficult repair if you know the tricks and will save you a lot of money as these clusters are expensive and secondhand one are not reliable. Take your time on this repair and be careful. If you struggle or something is unclear I will clarify and in extreme cases take one of my spare clusters apart and make a video for youtube.