Older site ranking worse than sites new to business, what am I doing wrong?

I've had this site since early 2008, with this domain name since 2009. For many terms it ranks well(macbook repair, macbook repair new york, macbook logic board repair, etc), but for certain terms(iphone repair new york, ipad repair new york) it ranks terribly.

This confuses me since the site caters to both, adn they are both in the same industry. Some of the sites that have popped up look good, but LOTS of the sites that surpass our rankings have only been around for a year or two, and are quickly thrown together looking bunk.

I've tried some white hat SEO in the past from reputable firm but the ranking stayed the same or went down.

Here's what I've done and accomplished so far:

a) Write complete content on all the pages.

b) Regularly update the blog, twitter, facebook, youtube page.

c) Post content on other webforums to help people solve their own problems, with link in signature on site

d) 1000 youtube subscribers & 400,000+ views without buying any of them on fiverr

e) Linked youtube how-to videos to services on the website using annotations

f) Regularly post ads on local sites like olx, classifiedads, backpage, and kijiji linking back to the service being advertised.

I'm not looking to cheat, just to get off of page three for a service I've had online for years before other sites even went into business. I'm open to any type of feedback; it's hard to offend me, so keep it truthful! :-)