Yes, these are interchangable. Both of these cards are EIO, and will work in either printer. What kind of problem are you suspecting that you have with the nic card? Is it the 615 that you suspect has the issue? The reason I ask is that HP has found a known issue with some of their 615 network cards. If you have the problem that they have realized exists, and your serial number is within range, they will replace the 615 with the newer 620N.
Timothy N. Couch
A1 Printech
Anchorage, AK