Warranty or Guarantee?
It's still a Holga! And because of that, It's a safe bet that
your Holga will leak light, take out of focus pictures, possibly vignette seriously around the edges, the shutter may stick, the back may fall off ruining your film if you don't tape the heck out of it, the flash
may fire twice or not at all, etc
Most people will say all of the above will happen if you're lucky.
My modifications do nothing to affect dependability
So just remember, you're buying a TOY CAMERA made in China where there is absolutely no quality control. Each Holga is like a finger Print, no two are alike. and each modified Holga is made to order and because of that, I offer no guarantees or warranties whatsoever and can not be returned.