2005 350ZR Grand Touring Edition

Two month's back, when trying to put the top down for the first time since Christmas, I got the dreaded "hum, hum, no go". I read up on this forum and other internet sources and concluded I had the dreaded dead 5th bow motor brush burn out problem. So, fearing the worst, I just ignored it for a while.

A few weeks later, on a whim, I tried putting the top down again and lo and behold it worked. And, it worked a couple of times over the next couple of weeks. I figured it might be a temperature related issue. Not as in the "it won't open at 40 or less - I live in the SF Bay Area and temps under 40 are rare - but in the "at 55 the grease is thick and the gears won't turn but when it gets up to 60 they will" sense.This allowed me to inspect the 5th bow for cracks and check things out a bit. Nothing apparent.

But, like all good things, it soon came to an end. And now I'm back to it groaning a bit but no opening. And, I have to put pressure on the rear of the top and shove the back down on the body to get it to re-seat after I try to put it down or else the warning on the dash is lit.

Any experience in what steps I need to take and what order to hunt down the issue and get it resolved? The good weather is coming here in sunny CA and I drive this thing 60 miles RT to work and back each day. If it's over 60 and sunny, I like to have the top down. Hell, why buy a roadster if you don't?