Extending lifespan of INTV's?

[Zaxxon]

Has anyone tried things like adding a heatsink to the inside chips, different power supplies etc. to make these things last longer. I haven't had good luck finding a 100% working INTV or one that will stay working. Unlike CV's, when a INTV dies/overheats, it seem to be unrepairable.

[Bratwurst]

Now this is interesting. I can't offer any advice but I'm curious as to whether the nature of the INTV's design makes it eventually die out or not.