Hi,
I think you should contact Jon (owner of piezo) for your question, he might have a solution for you.
I've never used piezo on 3880/3885 but did it on my 7880/9800, also 2400 a while back ago.
I think the chip has problem.
When I purchase my ink set, I never purchase the cart from him if you are not in USA.
The reason why is there might be some firmware differential between region by region.
I'm from Hong Kong and I purchase my cart locally. Had a problem once but I just go right into the store and they fixed that for me, which is give me a new set of it.
Just don't feel disappointed from them, their B&W ink is awesome.
Aaron