This is a defect of the Samsung SV-5000W. I have this unit, and have seen it myself off and on over the years.
Or more correctly, this is a defect of Panasonic. A Samsung is a Panasonic rebadge. That info alone will help you -- especially if you've seen a bad-cap AG-1980P deck.
The Panasonic has something that affects comets/dropouts. These are technically not magnetic dropouts, as that would be inherent to the tape. These are within the VCR only.
- Magnetism of the heads can affect or cause it.
- Static in the air can affect or cause it.
- Sometimes it's from the unit not being warmed up enough. Leave the VCR on for an hour or two, try again.
- Sometimes it's from being on too long. Turn it off, and try again tomorrow.
Or do what I did -- get a JVC S-VHS deck.
I mostly use the 5000W for SECAM now. Rarely for PAL, unless the tape simply reacts better the Panasonic transport.
If this is happening 100% of the time, know that it's not normal. But given that it's Panasonic, bad caps are possible. You can always ask TGrant for his input (and he may or may not have the ability or willingness to fix it for a fee).