This is a normal problem with this digital dash and most all digital dashes. The best place I have found to get it fixed is www.mrwhizard.com. It is only $149 including shipping and they will have it fixed in a couple of days. They also tell you how to take it out. It is not a fuse problem but a circuit problem. I have heard nothing but good things about this company. I haven't sent mine in yet though.
Hey, This is a pretty old thread, but I'd like to give any people that stumble onto this thread a chance to fix their digital dash for a little cheaper(50 cents roughly).
For anyone that doesn't want the full reasoning or how-to.... I just replaced the 50V 43uF electrolytic capacitor on the power supply board--- you have to use a 43uF electrolytic capacitor, but the voltage can be anything 50v or higher (the shop I went to only had 63V so that is what I went with). Also, remember polarity, the negative side of the cap faces the inside of the board.
the oil, tach, battery, and temp are all vacuum florecent displays (VFD), and are all supplied from one power supply (the speedometer, odometer, and turn signals are LED's, so their power supply is very simple). VFD's run on a high AC voltage, so their power supply is relatively large and a bit more complicated. The only thing that can keep all of those things from working when your speedometer and odometer are working is that power supply. When I would smack the dash, sometimes those indicators would come back on, so I first started searching for bad solder joints on the power supply. I touched up on all of them with no luck. So my next thoughts went to a part dying.... and the prime candidate is a capacitor. There are 3 capacitors on the board, but only one of them was really likely to go out(the electrolytic). Electrolytic capacitors tend to dry up and i'm thinking that banging on the dash knocked its insides back into place.
Things you'll need:
-Tools for getting the dash out(screwdrivers and sockets)
-50v(or higher) 43uF electrolytic capacitor (can be ordered if needed)
-Soldering iron(can get cheap ones for maybe $15 or $20 from radio shack)
-Solder sucker or desoldering wick (probably radio shack as well-- cheap)
Here is a very very brief how to for getting to/identifying the power supply, assuming that you've already removed the dash from the car. I haven't written very many how-to's so best of luck.
You'll need to take the metal plate off of the back of the dash, there may be something like 8 screws holding it on. Once the plate is off you'll be staring at a board with a bunch of solder joints. this is the board with the power supply on it. It is held in by 4(?) star screws, and has 2 flat gray cables coming from the sides. You'll need to take the screw out and remove the cables(be very careful here, I broke the plastic pieces that fasten these cables on mine- but I haven't had any issue with them working their way off). At this point you will be able to pull the board off and flip it over. Once flipped over you will see one board (maybe 2x4 inches) sticking off of the main board, this is the power supply. It is soldered to the larger board at a number of points across the top and bottom. You will need to desolder these. Once you've desoldered all of the pins you might not be able to simply lift the power supply off, if this happen just slip a flathead screwdriver underneath the supply and gently turn it.... do this down the top and bottom and you should be able to just pull the supply off. At this point you can replace the capacitor by desoldering the old one. They keep it on there with some type of goo that I assume is there to keep it from vibrating.... I used a pair of needle nose pliers to pull it off of this goo. Solder the new capacitor in, with the negative side facing the inside of the board, and resolder/reassemble the rest of the board.
I really recommend trying this.... especially if you already have all the tools to attempt this.... 50 cents vs. the $150 to ship it to one of the online repair places. This might not work 100% of the time, but in my run-in with this problem it solved it.
hey my digital dash nothig works but the speed, mileage, light bulb ones turnsignals. the other ones dont its in my 91 blazer. replaced the green mother board and it didnt do nything. can u plz help me. its a pain in the butt taking it all apart and putting it all back together for it not to work..can u please email me and help me? my name is samantha. email is pillowcase_1993 @ live . com. please help!!
if you have not fixed the problem yet i can give step by step instructions to fix the problem i have two of the with the same problem and fix them both and they both had the same problem
I would like those instructions, please. I have my daughters '92 GMC T15 Jimmy's dash on the bench right now. Before, the dash would light up as normal untill you put on the turn signals, or turned on the park/headlights. Then the dash would go dark. I have removed the power supply board and inspected it under a magnifying glass. The joints all look good. Another forum I broused said to replace the two 3328 power transistors, but they seem to check out OK on my multi-meter. Anything else you could add would be very helpful. Thanks.
My S10's cluster was completely dark. I followed the instructions above to fix the "corner" displays, and now my Tach, Oil Temp, voltage and gas displays light up just fine. The Odometer displays.... but not the speedometer !
I already went over the entire circuit board and re-flowed every solder joint.
Any thoughts on what I need to do to fix the speedometer display when the rest of the cluster lights up just fine?