Just recently placed an MRC 1624 decoder in an F-unit and could not get the decoder to set a new address, or any thing else for that matter. It worked perfectly fine on Address 3, just wouldn't take instruction.

I tried resetting (CV 125) with no luck.

I am using an EZ DCC system and had a Soundtraxx PB 100 in the line to the programming track.

Just for the heck of it I bypassed the booster and then I was able to program the decoder.

Don't know if this may help others but I thought I would pass it along.

Have a good weekend

Espee over Donner