The MKV TMR panel in question has a full compliment of SDCCG4AHD cards. One has developed a problem and we would like to change it out for a replacement, however the only replacement we can find is an SDCCG4AGD, which is an earlier revision. In the past I have changed out cards with newer revisions as the OEM always maintained this path would be kept compatible. I have not used an earlier revision replacement strategy. I am reasonably confident that using a GD to replace a GH will be OK. I see nothing in the PROM directory definition files or in IO configurator that would indicate any prospective issues. Has anyone had a similar experience or can offer some indicators on the probability of success before I start off on this path?