I have an existing system that has several 412 TDL boards in it. 2 of those boards have intermittent issues. I purchased 2 "working" boards from a reputable seller on Ebay to replace them. I tried the cards last night and neither one would work. All phones flashed the message waiting light but never booted. Popped the old cards back in and they booted fine. I have been working on Magix for @22 years but am I overlooking a potential software version handshake between these cards and the processor?
I am leaning toward faulty boards?

I am new to this forum but I have been in the industry since 02/1997. Mainly Avaya, Mitel, Panasonic, and NEC. Glad to be here!