You can vote the board out at the next election (be prepared to work hard! people end up as regulars on the board because no one else wants to do the work)

You can insist on reviewing the books; check your bylaws for regular reporting schedules, and if one isn't coming up, at least ASK if you can see interim financials, or at the least a list of expenditures). If they haven't reported regularly on the financials, that's surely a violation of the bylaws (if not of state law), and you can bring a lawsuit against them (and you wlil pay for their defense).

You can all go to attend a board meeting and ask questions, make it clear that you're watching, volunteer to do the legwork of finding plumbers, etc.

I live in a small, self-managed co-op, so my experience is vastly different. But the yearly financials reporting tells me what is happening to our money; I know where it's going. or at least where it is SUPPOSED to be going.

Your books should be audited, too (ours aren't, because we're so small and everyone is one the board). Get those, and review them.

Also, your state (province, I guess, since you're in Canada) may have some sort of agency that could assist you; I know NYState has an agency or part of the attorney general's office that deal w/ condo & co-op enforcement; maybe they could have a checklist of steps you can take to investigate.

Also note that in the last 5 years, many costs HAVE gone up for homeowners--heating fuel, electricity, INSURANCE (at least in the USA, it's gone through the roof)

A condo is a democracy; the best thing you can possibly do is get elected to the board at the next election (and ATTEND board meetings between elections).

At 5 years old, even a non-maintained system shouldn't need complete replacement, should it?

also remember--the choice isn't the two extremes:
corrupt, or normal.

There's lots of area inbetween--competency (or lack of it), vision, a really crappy contract or loan or something that locks the corporation into a payment schedule that ties up all the income....

Start by looking at the financials for the last 5 years. See what's going on.

(in my small co-op, we've had assessments and maintenance raises in the last 2 years, due to rising general costs, and one big expenditure)