Overheating Trip Computer - '94 LHS

[Ron (2)]

Any electronic wizards out there?

My problem originally surfaced a couple weeks ago when the fuse blew for the instrument panel. I replaced with original size 5 amp, only to have it blow 2 seconds later. Probably not a smart move, but I then replaced that with a 10 amp. The gages then worked fine, until today. The "trip computer" LEDs started flashing off and on, almost like a wire was loose.

I pulled it apart, and there are no real wires, it is all a printed circuit board. (attached is a link to a picture of it). http://www.summit.net/home/geer/DisplayBoard2.jpg

At first I thought the burned-looking spot at the lower right of the display signified a problem, but after plugging the board back in, and starting the car, I found out that the component in the upper-right gets hot really fast. Not sure if it is bad, or a short somewhere else is causing the problem. It has what looks like a heat-sink attached, but I am sure it is not supposed to get that hot.

The fuse draws .02 amp without the trip computer plugged in, and 2.5 amps with it. That is obviously too high. (actually it drops to about 1.2 amp when things get hot)

I probably should just try to find a board in a junk yard, instead of fooling with it, but I would prefer to pick up a part at radioshack if that is all it needs..

Thanks for any ideas,
-Ron

 

[Steve m...]

That chip looks like a voltage regulator to me. Check the top of it for markings and see if Radio shack has a replacement. They are usually called 3 pin fixed voltage regulators. You will need to know the voltage rating (output & input for it). Radio shack carries some of these in different ratings. The dark area on the display is probably normal for a Electrolum... type of display. Since they are basically in a vacuum it has an absorbent on the glass that keeps the oxgen level low inside the display. I've seen these displays on ebay for around $20 I believe.

Stevem...