Prosignia 740 vs Proliant 1850R

[Richard Woodman]

I inherited a Prosignia 740 that fails to POST and won't read the floppy drive when put in disaster recovery mode (SW 1, 4-6 ON). When I search for Prosignia 740, I get hits for the Proliant 1850R as well. Since the cost of an 1850R system board is $200 less than for the Prosignia, I would like to use one if they're the same. Anyone know if the 1850R system board fits the Prosignia chassis? 1850R is a rack-mount and the Prosignia is a tower but if they both use the same mounting points and the riser card interface is in the same location, will they interchange? Photos of the 1850R system board appear similar to the 740 but I'd like to know if they interchange before I buy. Thanks for the help.
Richard

[Richard Woodman]

Update:
The part number on the motherboard is 157292-001. When I searched using Prosignia 740 6/500, it returned a match to the server type but with part number 387760-001. Other than the part number, is this essentially the same board? I understand that the part number might be different due to differing chipsets or something but will it fit the chassis? This board is $259 where Compaq/HP wants $319 for the other (correct part number). Please help resurrect my server. Thanks.
Richard