Retrobit 3-in-1 RetroAC SNES/NES/Gen AC adapters... pure garbage?

[Az]

I decided to clean the closet of a few loose SNES systems I had picked up over the years. Most were picked up missing AC or AV cables so I bought a lot of cheap no-name AV cords from eBay, along with a lot of 10 Retrobit brand AC adapters. The AC adapters are the 2-in-1's, 9v 850mAh with 2 tips to either fit a SNES or a model 1 Genesis.

I finally went through all my OEM AC adapters and started using the Retrobit ones. Well, tried to start using them anyway. Although I've not went through all ten the five or so I've tried were pure rubbish. They were tested on multiple SNES systems and all ended up with bands of horizontal interference on the TV that slowly crawl down vertically then repeat. At first I thought maybe I had some major interference going on with the outlet I was using so I tried it on a different TV in a different room that's on a completely difference circuit breaker and it still acted the same.

These were all brand new, still sealed in the retail package. Surely I'm not the only person that's ran into this problem. Has anyone else had any experience with these things? Is there something that can be repaired/replaced on them to remove this interference? I haven't tried them on a Genesis yet but I figure the results would be the same.