Hi, I bought a Fluke 8506A to which the thermal converter was removed, in a second time I bought a Fluke 8505A with the heavily mechanically damaged box, with the intention of transforming 06A into 05A. I immediately noticed that the controllers of the two machines have the same EPROMs, same jumper and therefore I deduced that the differentiation of the two multimeters could not be there, so I verified that all the boards of the two devices had the same pn. I placed the 06A boards in the same position as 05A but without result: Inserting the ac / dc converter board gives me an error E and tells me that the machine is a 06A and that I can only put the thermal converter. I assume the bus is the same, so the question is: where is the problem? Thanks Luciano Luciano P. S. Paramithiotti timeok@timeok.it www.timeok.it *****************************************