Samsung SV-5000W Worldwide VHS Format VCR
A soultion of the snow problem
I've experienced the snow problem and have tried several methods.  Head cleaning: Not solved.   Reset: Not solved.   Unplugged the Samsung VCR for 12 hours: YES! The snow has completely disappeared!  Thanks to the tip by J.L. Alberti.    Follow up:  The same snow problem occured after multiple tests.  Unplugged the cord for a minute and the picture returned to normal.  Heating was not related with the problem. Digital noise on the conversion process might cause the snow and it could remains in the VCR.  So whenever you see the snow, unplug the cord and let it sit for about 30 seconds to a minute and try again.