Old Sun diags questions (4/300 and 3/200)

Couple of questions on old Sun machines (well, parts). On a Sun 4300 CPU board, I'm getting the "EEPROM Write-Write-Read-Read test error PA=0xF2000000 VA=0X00FF8000 Exp=0x0000005a Obs=0x00000000 (looping)" error. Looking on the Web and Usenet seems to show that this has happened a couple of times, with some reference to possibly being the NVRAM (although the most comprehensive posing set was in German :(). This seems a bit odd, though - on my other Suns it calls the NVRAM the NVRAM, so I'm wondering if this is something else. J1900 1-2 is connected (4MB SIMM option), so it shouldn't be that (or is there something else needed to be done- not sure if this is a 4/330, or if there is any board-level reason that it couldn't use 4MB SIMMS). Another question- so far I have had two Sun-3 era machines (a Carrera CPU in a CADDstation and a Sun 3/200 CPU) develop "all lights on" catatonia. Is this a common problem with Sun-3s? I'm wondering if I should take the time to trace out the 3/200 board (preferably with hints on where to look), give it away, or junk it (I have a working 3/110 system, so I won't be destitute of Sun-3s).