After all my preaching and all my help with other moms, I CANNOT get my son to consistently sleep beyond 4:30am (sometimes 4am... 3:15am the other day). That is right. I am up at 4:30am most mornings. I have a routine. I have tried putting him to bed 1/2 hour earlier for 5 days. I have tried putting him to bed an hour earlier for 5 days. I have tried putting him to bed 1/2 hour later (when he falls asleep on his feet). I REFUSE to go and get him before 5am.
I struggle to feed him dinner and I struggle to feed him breakfast.
When ever you have a baby who was a great sleeper and now seems to do a 180 turn on you, I always look at a few things. First I make sure that their daytime schedule is appropriate for his age. I believe your son is now around 2. Anywhere between 2 years and 4 years is when babies tend to stop wanting to nap. If he is getting a big nap in the afternoon it may be the reason why he is not sleeping later in the morning. As children get older they require less day sleep but if they still get that day sleep it will effect how long they sleep overnight. If he is currently getting an afternoon nap, I would start by reducing the length of that nap by half an hour.
Secondly I would look at what time he is going to bed. If 7pm is your current bedtime, it may have been fine when he was younger but he may not longer need 12 hours of sleep per night, so possibly moving to an 8pm bedtime would be beneficial.
I would also take a look at his room atmosphere. Make sure there is no light peaking in from the curtains at the 5:30am mark. Also, make sure that the temperature is optimal and that he is not overheating or cold.
There is always something, be a detective and try and figure out when this started. Was there a situation that occurred? Was he sick? Is he teething? I had a previous client who lived in an apartment and she realized that her daughters bedroom was attached to the tenants next door. The neighbours had their alarm set every morning for 5am and this woke the baby but by the time she went into the babies room the neighbours alarm was turned off so she didn’t figure it out for the longest time. Could be a similar situation...a dog barking, a car starting outside etc. Try and pay attention to what’s happening at that time of the morning around your home.
I also know you have been using the white noise machine but now that he is 2 years old you may want to switch over to the gro clock, This is the glo clock that has the picture of a moon and sun so baby learns when is night and day. Now that he is no longer a baby, he may need to move to the next step. Have a look http://www.gro.co.uk/Gro-clock.html.
And lastly, normal overnight sleep for a child that is 2 years od age is 10-12 hours. And some babies do sleep the minimum of 10 hours. However, you do also get babies (like my daughters were) that they have a set wake up. No matter what time you put them to bed, 6am is their wake up. Some babies are like this and we have to just accept it. The goods news is it doesn't last forever...now I have to beg my kids to get out of bed!
Hope this info helps!