I have a PE R420 which needs a new system board. There is a sticker on the mobo with DP/N OCN7CM. Do I have to use this exact model or will any R420 motherboard work? I say this because I can find 100's of R420 mobos but only a few with DP/N OCN7CM.
That part number is for a v2 board, but they went up to v4. It looks like we had some board part numbers that were different for the Asian region, Brazil, and Russia. I can't say if those were different for some compliance reason, or if they were electrically different somehow.
The part number I'd be looking for is K29HN. It's a v4 version of the board you have. Disclaimers all said, I'd expect any of the R420 boards to work, since they'd all be validated against the same pool of devices.
Let me know if this helps, or if I successfully muddied the waters and prompted more questions!