Digital dash disappeared

[Jetjock]

My digital part of my instrument cluster started to fade out on me a few weeks ago and then just disappeared from view. My light control works as I can see the brightness go up and down. Is this something internal with the dash or is the data transfer part gone bad? On occasions, I can see the speed and the fuel level coming through. Any thoughts and suggestions?

[Franke]

Jetjock, The FSM in section 8A page 82-1 shows that the Digital display is connected to the digital display circuit board and then to the CCM (central control Module). You might have a bad LCD power ground to your circuit board at the board or wiring to ground at point G201. I think that ground is near the drivers side kick panel somewhere. I would very gently remove the display and clean all contacts and re-seat the connectors etc. Sometimes this kind of problem also shows up as a bad solder joint as well. Consider also the SIR warnings as you will be working in the dash area.

[scottfab]

I've looked at the schematic on page 8A-82-1 and agree check the ground but do it at the connector at A7. It in fact could be a poor
ground at G201.
Also you'll need a scope to look at the various data and clock connections. While I have no direct experience with this LCD display I can tell you from experience with other LCD displays that it sounds like a missing LCD bias clock.
If you are not comfortable troubleshooting this at the component level you'll probably need to get a replacement display board.
If you do and the new board works then make sure to plug the
old one back in at the end to confirm it still is defective.

[Jetjock]

Thanks, guys. It gives me a starting point. I'll let you know.

[batchman]

On occasions, I can see the speed and the fuel level coming through. Any thoughts and suggestions?

LCDs need a backlight to work. If you can sometimes/sort of see an image it may be the fault is in the backlight, connections or (hopefully not) a component.

Good luck,
- Jeff

[scottfab]

LCDs need a backlight to work. If you can sometimes/sort of see an image it may be the fault is in the backlight, connections or (hopefully not) a component.

Good luck,
- Jeff

The OP writes, " My light control works as I can see the brightness go up and down. "

That tells me it's not the backlight. But who knows.

[batchman]

The OP writes, " My light control works as I can see the brightness go up and down. "

That tells me it's not the backlight. But who knows.

You are so right - I got focused on the faint image comment. Will also agree - But who knows.

Where is this guy Who when we need 'im...?
- Jeff

[Franke]

In the words of some great comedians.... Who's' on first.

[-=Jeff=-]

I had that issue. turned out to be the LCD panel itself

[Jetjock]

That's what Gordon said. He said it was the cluster. However, the darn thing worked this morning whilst in the wee hours of 4am while driving to Nashville. The whole dash would go dark with no interior lights and when I flip the light control to full inside brightness, everything came on. When I turned off the light control, it stayed on for a little bit and then went out again. Finally, it stayed on for the drive to the airport. I don't think that the cluster would cause the interior lights to go out so I could have two problems. The light rheostat and the cluster. Fortunately, I know how to fly instruments.