I've found some research reguarding my '89 S15 Jimmy's digital dash. The speedometer works once in a while if you hit a big bump in the road, or whack the dash.

I realize it's not a thirdgen, but I do own a thirdgen as seen in my sig, and know the S trucks mirror the Fbodys and figured the digital dashes would be similar.


Supposidly it's a bad powersupply on the back circuit board, or a broken/loose solder joint.

I can't see any loose joints or broken joints. Maybe I'm not sure what to look for?

Anyone else know what to do? I can't justify the $200 to send it off to big fixed.

All I see is some heat discoloration on two large resistor looking things, and some red goopy stuff on a capacitor and diode. Is that indicative of a bad cap?


Thanks
-Paul

 

I can't really tell from the pic, but caps can "bleed" when they go bad. In any case, if you question it, replace the cap. It's only a dollar anyway from an expensive place like Radio Shack. As for the resistors: I had the same thing in an older audio amp of mine. From my investigation, it looks like the solder did not fully join to the resistor lead and over years got worse & worse. I actually couldn't resolder it -- the solder would not stick. I pulled the resistors and used a razor to scrape the outer few mils of metal from the leads and resoldered them onto the board. Problem solved for me.

 

I would recommend reflowing the solder joints on the big connectors mounted on the board. This is a chronic problem due to vibration. You won't be able to see the broken solder joints without using magnification, sometimes not even without a loupe. The goop on the cap is glue to hold it in place so vibration doesn't break the legs off since it is "tall". The discoloration under the those resistors is normal because of their size.