Phantom was global on those IIRC. If it were a phantom problem, it would be on all channels.
Ampeg, Crate and Audio Centron were part of the St Louis Music Company. When Loud bought the MI lines from St Louie Music, Loud chopped any comparable product to the Mackie line, allowing only the filler, low-end products to exist. Check Ebay and Craigslist if you want a direct replacement. You won't get any support for those mixers now.
Entry level mixers like the Crates, Tapco, Behringer, etc should be considered re-occurring purchases every three ot five years. If your mixer lasts longer than that, you are very fortunate.