I talked to the dealer and he told me that it could be a screw that wasnt put back in right. Something about how the screws that hold it in also ground it. Not sure I am going for all that but I am taking it up there friday to have his service manager "look" at it.

 

ya could be the case since so many grounds in the car are screwed down so if they do it right can use the screw for 2 purposes.
but for sure bring up the other issues to see what they say. The interior handles are a very common thing to fix, like the cracking dash

 

Can you send me detailed instructions on this procedure

 

I have an 07 avalanche that the Driver Information center (DIC) and the PRND12 LCD displays went out. I called the stealer and they wanted 390 bucks for a new Instrument cluster. Then I looked on e-bay and found numerous places that will fix the cluster from 125.00 - 200.00 bucks. I work in electronics and can replace components myself, so I called a few of the places on e-bay. All of them did not have or want to sell me a part to fix it and one actually said we don't replace anything. So I asked how to fix it and none of them would tell me.

So the odds of both LCD going bad at the same time are pretty minimal. I researched the www and found this post. So I took the cluster out and looked at the MOSFETS. Everything looked good. There was one small spot near a small transformer that was discolored from heat. I decided I would just for the heck of it try redoing all the solder joints on the MOSFETS, transformer and circuit board connector. Went out and plugged it in and everything works again.

The guys on e-bay are making a lot of money for about 5 minutes work on the circuit board.

 

You'd be surprised at how many TVs I've fixed by reflowing solder joints, especially those on Molex connectors and hi-heat areas like transformers.

 

I believe I have a fix that,well at least worked for me. Thanks to everyone's input on here and with the help of you tube on how to remove my speedometer. One of the transistor leads on the speedo circuit board came loose between both displays (PRND321 and Odometer ). if you look hard you can see the little gap between the lead and the board in the pictures. I just put a little dab of solder on that joint and everything started working properly. I will have to say that what people are charging to repair your speedo is fair considering that you can easily screw something up if your not careful plus the added stress on working on someone else stuff. I cracked a little piece of the clear plastic lens over the speedo but you cant see it once you put everything back together. Anyway here are some pictures of what i did to fix it, use at your own risk but hopefully this will save you some money. If you do have " service tire monitor system " after you reinstall it, just start your engine for a few minutes and the message will go away and it will work properly. your correct mileage, trip, oil life meters, engine hours will be current.

 

more pictures. I gently moved the needles on all the gauges by hand to the lowest reading then marked that placement with painters tape. I know this sounds getto but I used a fork with some paper behind it so wouldn't scratch up the overlay to remove the needles but it worked. then unclip and lift the white plastic with the overlay still attached and you will see the speedo motherboard and all the components. to reinstall the needles, you can put the needles a little higher than your markings using some junk mail or whatever to provide a little space between the overlay and the needle so it doesn't scrape the overlay when the needles are moving. then very gently you can push the needle down to your mark. or if your hands are very steady, you can just put them right on your mark. When you install it back, the gauges will go back the proper position.

 

Congrats on your repair. Repairing SMT components can be a bit tricky. Too much heat and you can lift the land.

Thanks for the pics.

 

This is great stuff. I have a 2007 Yukon with the same issue but I have been completely unsuccessful at removing the speedo. I was able to remove the side vent and top cover around the speedo but I can't get to the back 4 bolts actually holding the speedo on. Any chance you can give me pics and instructions on how to get to those 4 bolts?

 

07 08 09 Tahoe Silverado Speedometer Removal Gauge face install guide - YouTube

you can search for 07 08 09 10 tahoe speedometer removal for gauge face install. Its meant for you to change the color of your gauge face overlay but it will help you do what you need to do.


I used this link on youtube to help me me out. after you remove the 4 phillips screws covered up by the left and right vents and upside down on the hump under the dash where the speedo is, there are 4 bolts holding down the speedo. I think its 7mm. Two on top and two covered up by trim thats over the gauges on the bottom. The clips holding down the trim ring around the speedometer are on the bottom and are very tough to remove. If you carefully slide the screwdriver along the bottom of the trim , it should pop out. I wrapped electrical tape around the screwdriver to prevent scratching up the dash and the trim