I finally got around to replacing the dead LCD screen in the central infocentre binnacle in my 156 GTA, and thought others who are having the same problem might appreciate how I went about fixing what is apparently a common problem for the GTA and facelift 156s. It was actually fairly straightforward, but with the usual swear-inducing faffing-about typical of any Alfa meddling caused by tight spaces, dropped screws, the usual nonsense.
I bought a replacement screen online, think it was from "Allway Electronics" - standard made-in-China stuff, but specifically for 156 and 147 screens. They are readily available and not too expensive, if I remember it was maybe between $60-$80 delivered. (I bought it several months ago, so can't remember) [UPDATE - it actually cost $120, went back and checked).
First - purely out of an abundance of caution given I would be moving wiring and connections, I disconnected the battery negative terminal. Then I turned to extracting the binnacle. You only need to undo the two hexhead screws in the vent area closest to the windscreen. Be very careful not to crack the vents or housing - it can be pretty brittle being exposed to sun all these years. Even light pressure on the vent ribs can break them.
Binnacle just lifts up and out, has 4-5 flexible metal clips keeping it down but just requires gentle levering out. As the screen unit is still plugged in you'll only be able to lift it up out of the hole, enough to turn it around. There is also a second thinner cable from what I think is a temp sensor at the back of the binnacle housing, which will also be plugged in, so be careful not to pull too hard.
At this point, you'll need to remove the glovebox -just half a dozen or so screws holding it in - so you can pull the glovebox forward and down (no need to pull it out completely). This will give you access to the wiring and plastic connection from the screen unit - the connection is a white box mounted on a metal rib on the right hand side of the glovebox, held on by a plastic slide mount. You can pull/slide the box out of the mount to get access to undo multipin male half from the female half of the connector. You'll need to use a screwdriver or similar to push in the retainer clip in the side of the connector box so you can prise the two halves apart. Once undone, you'll have more play to remove the screen unit from the top half of the binnacle.
You can now lift the binnacle up enough to turn it upside down so you can unscrew the unscrew the binnacle top, which contains the screen unit. The top is held on by 5 little philips head screws holding it together, two each side and one along the back edge. Separate the two halves of the binnacle and put the bottom half off to the side out of the way.
Flip the top half upside down, and undo the four screws holding the black rectangular box that houses the screen unit, and remove the black box. Remember to pull the cable all the way through the dash and out the hole - it passes through a rectangular gap along the front side of the hole in the dash.
The black housing has four plastic tabs holding the innards in. Push them in and the screen unit slides out. Separate the inner sections carefully - there are 3 or 4 separate really fine multipin connections between the main components.
The screen itself is only held to the circuit board by two flexible plastic tabs containing the wires. They are connected in two long skinny white plastic connectors, locked in by little plastic tabs on the end of each connector, Pull them to release the screen, slide in the tabs of your replacement screen, and then push the tabs in to lock the screen connection down. No soldering or other trickery required.
Reassembly of the screen unit, and binnacle is just the reverse of disassembly. Don't forget to plug the screen cable back into the connection near the glove box (feeding it back through the hole correctly and down to the glovebox can be a bit tricky).
The pics below might also help.
1 - my original dead unit in the car.
2- binnacle lifted up out of hole in dash, showing underside where the screws holding binnacle top are located.
3 - the new replacement screen next to the dead screen unit in its black housing, which has been removed from the binnacle and is out of the car.
4 - the main inner parts of the screen unit out of the housing and separated.
