I have owned my Soundlab Ultimate IIs since 1998.My panels are the originals with the same back plates from the factory.I have "never"had a problem whatsoever.Now,if I listened to and believed every negative thing has been said on this forum I would not be enjoying the best speakers I have ever owned.I am off the merry go round of audio.
You may have the original mylar panels and power supply and if so, do not upgrade or your good record of no repairs may be dashed.
My first pair of Sound-Lab were sold to a friend about that same time and he has had NO problems.
Me? I had to have the upgrade (thin mylar and higher voltage) and after that first modification it was failures and back and forth to the factory many, many times while my friends pair continued to work without fail.
Sure, mine sounded better when it worked but his worked all the time.
I understand Sound-Lab have this resolved now with the new design. Brian (Essentialaudio) would know better than me and perhaps can chime in.
I've moved on but hold Sound-Lab near and dear to my heart. When they are right they do things no other speaker can and deliver emotion and micro detail that's addictive.