[Yaesu] FT301D display failure

[Dave Edwards]

I think it is common knowledge that the old FT301D has issues with the display. Many segments are <usually> out.
Mine held out for a long time, but I finally got one segment in the 100 cycle digit out. 

My question is this.....Does anyone know if this is typically caused by the display, the driver chip, or a bad solder joint. 
Since they fail often, I am sure there is a known cause. 

Thanks for any discussion on the subject!

.....Dave