[lcaillo]

http://www.hometheatershack.com/for...-reliability-crt-rp-convergence-circuits.html
http://www.hometheatershack.com/for.../5600-crt-based-rptv-convergence-repairs.html

The threads above deal with this issue.

I fix lots of Sonys for this problem as well as most other brands. Samsungs and Philips seem to be among the hottest running chips, and they seem to break more than, for instance, Sony and Mitsubishi. The number of problems also relates to the number of sets sold in particular market. All of the convergence output ICs are made by the same OEM, Sanyo. There are some differences in the loads that some sets provide, how hard they are driven, they setup, the heat sinking, and quality control in building the sets.

 

[lcaillo]

The static electricity that comes with 30kV on the anodes likely does not help. I would not be concerned with the dust unless it is really severe. Generally it is harmless to the set and its components. Just clean the optics periodically and leave the rest.