Steve Tippins advises graduate students whose dissertation chairs have gone silent to first request an explicit meeting, then escalate to the department chair if ignored. Document every contact attempt. Many universities require faculty responses within two weeks.
If you have tried to be proactive and just aren't getting any responses, I would try to contact again and say, "Can we have a meeting so I can talk about what I can expect and what I'm supposed to do here?" So you can get them on board. Now, every once in a while you get a chair who just doesn't respond at all. That's when you have to talk to advisors at your school or department chairs and say, "What is it I'm supposed to be getting from my chair?" There's a number of universities out there— typically they are distance learning schools— which have parameters. You must respond within 2 weeks or something like that to student inquiries. This is when we start keeping track. I sent them an email on this day. They didn't respond until this time. So you're building a case for getting external to your committee support to moving forward and/or finding a new chair. Drop the word help in the comments and I'll send you the link for our free dissertation help community.
