I had mine (92 140) rebuilt and new bulbs installed, I had the issue of it flickering which was a common issue. It seems the electrolytic is in the voltage regulation circuit of the cluster, and a drop of voltage shuts down the regulator. They returned all the parts and bulbs which included some sort of power transistor, the much discussed capacitor, and a smaller transistor. I would replace the exterior temp bulb, since it is soldered in on the non digital version. I also have all the tools and skills to repair my own cluster but decided to have it done (Programma) is local and got it back the next day with a two year warranty $300. The 129 and 140 clusters are not interchangeable per
http://mbcluster.com/