1/2 MFA Cluster

[moonranch]

Just installed my cluster this weekend(thanks Baz), works great and was a fairly straight-forward install. Only thing is that the display seems a little dim. Is there a way to adjust the brightness so I can see it better in direct sunlight?

 

[dzcad90]

When I installed my half MFA cluster in my '03 Jetta, it was pretty easy to see in the light.

If you have your headlights on, the dimming rheostat controls brightness of the cluster. There is also a photo sensor in the cluster that controls maximum brightness. If the sensor thinks its dark, it will keep the lights dim.

I forget, but if you look in measuring blocks of the instruments there might be a reading for the photo sensor. You can see if it's high and if so then the photosensor might be dead.

 

[moonranch]

Don, Thanks I will look for the photosensor. The rheostat works fine when the headlights are on, but when I turn the headlights off the displays stays at the same brightness it was last adjusted to.

 

[Nihilator]

If the MFA is dim around the corners more so than in the center, then the LCD screen that generates the characters (which are backlit by LEDs) is aging. It happens, worse in some clusters than others, and there's no fixing it. The MFA screen is not what you'd call "user-serviceable". Your only real hope is to find an MFA cluster that just didn't happen to age as badly as your current cluster.

It does not make sense that the MFA stays at the same brightness level it was rheostat-adjusted to when you turn the lights off. When you turn the lights off, the MFA should brighten because it thinks, since your headlights are off, you must be in daylight. It will then use the light sensor to modulate the level of the MFA's brightness.

--Chris

 

[moonranch]

It does not make sense that the MFA stays at the same brightness level it was rheostat-adjusted to when you turn the lights off. When you turn the lights off, the MFA should brighten because it thinks, since your headlights are off, you must be in daylight. It will then use the light sensor to modulate the level of the MFA's brightness.
--Chris

So it seems like the MFA thinks my lights are still on after I turn them off? Once I turn the headlight switch off, the rheostat does not effect the display. I will play with it some more and see if I can figure it out.

 

[graeme86]

Hi Chris (Nihilator)

I found this thread which mentions there might be a byte that changes the MFA contrast level:

http://www.gti-tdi.de/board2/index.php?page=Thread&threadID=2069

I can't seem to match up the numbers with my Immo 3 clusters.

Maybe you might recognise the clusters mentioned?

It may just be where the information is stored in the dump from the sensor readings, but may not be able to be "user adjustable"

 

[moonranch]

Update:

Well, I finally got around to looking into my MFA lighting issue. So I took the cluster apart to see how things were put together. The MFA is built in several "layers". On top is the LCD(pic 1), next is a plastic sheet that has a a bunch of horizontal lines, not sure what it's for(pics 2), then there is an almost opaque piece of orange plastic(pic 3) this one seems to be some sort of diffuser that makes all the LEDs behind it(pic 4) look uniform. But since this piece seemed to block out a lot of light, I decided to replace it with a piece that was much more transparent(pic 5). The LEDs now look more like "point sources", but once the piece with the horizontal lines is back it gets better(pic 6), and when the LCD is back in place, it is hardly noticeable(pic 7). Bottom Line - Problem solved. I cant read my MFA during the day and in direct sunlight.

Pic 1

Pic 2

Pic 3

Pic 4

Pic 5

Pic 6

Pic 7

 

[dzcad90]

That's how an LED backlit LCD works. The LEDs are hot all the time. The LCD in this case kind of acts like an inverse display, basically only letting light through that forms the carachters. Generally there's a background filter, and in some cases, a polarizing filter.

Nice work though!

 

[jjcsnlynn]

MFA Backlight Questions

then there is an almost opaque piece of orange plastic(pic 3) this one seems to be some sort of diffuser that makes all the LEDs behind it(pic 4) look uniform. But since this piece seemed to block out a lot of light, I decided to replace it with a piece that was much more transparent(pic 5). The LEDs now look more like "point sources", but once the piece with the horizontal lines is back it gets better(pic 6),

Where did you get the orange sheeting from? Anything special characteristics to the that sheet?

Also, how did you removet he LCD layer? Does it just pull out?

 

[Powder Hound]

Looks to be a flexible connection on the bottom (such as used in laptop wiring) so the LCD was just lifted and laid down out of the way.