Help with issues with car HUD

[glacier985]

Hello I am trying to diagnose and fix some issues with my cars HUD (heads up display). I know this issue is located to the gauge cluster. The car is a 1994 Nissan Altima GLE and I have owned it since 2001 and up until this year the HUD worked fine.

The issue with it is very odd, the speedometer only works when it is warm outside or the inside of the car warms up enough to heat it which is usually about 30 minutes. So far I have tired to diagnose and fix the issue myself, but have had no luck. I tried this test thats for a 240sx. This lead me to replace two capacitors that I thought went bad, but to this did not fix the issue. Nothing on the board looks or smells burnt or damaged, and it has not been dropped or gotten wet.

Now here is the odd part, well to me at least. If I heat the board up with a heat gun the speedometer well work after about 30 secs. This makes sense with the way it is working, but with my limited knowledge of electronic circuitry I don't know why it does this.

I will be getting pictures later today when I get home from work, I just wanted to get the thread posted before I forgot.

 

[CocaCola]

Until pictures are posted, you might want to go through and heat up all the solder joints... If you have some flux handy it's a good idea to put a little on each joint before you heat it up... A flux pen works well for this... A little fresh solder also isn't a bad idea if you can't get the joint to go bright and look new...

The reason for this is that there might be a broken solder joint, as the board heats it slightly flexes/warps/expands and when that happens the connection is made... When it cools again the connection breaks...

Faulty solder joints like this were pretty much the most annoying repair and far from uncommon when I was doing repairs on a production line...

 

[glacier985]

Here are the pictures.....they are a bit large.

First the front and back of the HUD board


And the back of the speedometer

 

[glacier985]

Only about four months later have I gotten around to working on this. So I got a flux pen and reheated every joint and added solder where need. This was a pain and unfortunately did not fix the issue. Is there anything else? I'm am my wits end with this.

 

[davenn]

OK so knowing its a heat related problem and heating the whole board brought things right reasonably quickly. You have 2 further test choices....

1) find a way to safely heat individual components till you get the desired results

2) let the board warm up normally till it works and then use a can of freezer spray with its fine tube and cool individual components till the fault shows itself

Dave