Funny you should post this- I just received a set of empty carts from IJM for an Epson 3880. The LM control chip was the only one not working for me too (I have a LM chip from the last carts I purchased a year ago that does work, so I could swap with the defective one). VLM worked (at least the spare one IJM kindly sent in anticipation of problems, not the one mounted on the new cart). My Epson 3880 is about 3 years old. I have already asked Wells to send a replacement LM so I am all set.
Best, Wayne