I ordered a new laser tube from the same eBay seller (qiandingzhensatisfaction) - formerly Love-HappyShopper, I did last time, as they are fast and very reasonably priced. Their emails are sometimes a bit confusing, but they have lived up to their advertising in the past, so "go with what you know"!
I installed the tube today and it was like the 4th of July coming 4 months early - fireworks everywhere.
I rechecked my wiring and carefully retested. More fireworks.
Here is another shot.
I jut finished emailing the company. I have been told they are very good about quickly replacing bad tubes. We'll see what happens, and I will let you know.