He’s talking about msr16s Dolby cards, nothing to do with 238 cards, completely different.
Somewhere I have an extensive Dolby s card repair description that I wrote years ago. I’ll try to find it, there may be a copy on this forum somewhere.
You will not find any new replacements, and fixing them is not easy. Maybe buy a parts machine and get 16 spare channels of cards, I did that years ago. Buying a parts machine will be simular price to buying 1 new card.
I think you sent me a pm about manuals, I di have one but only a hard copy, scanning will be a big job
Alan