Fitting FPU to Apollo 1230 Mk2 - reboot loop :(

[TCMSLP]

Hi All,

I have an old Apollo 1230 Mk II, no SCSI, single SIMM slot fitted with 32Mb, a 50Mhz 68030 and a Mach 210.

The board has a PLCC socket for a 68882FN FPU.  I've bought a suitable FPU (68882FN40A - I don't believe a 50Mhz part was ever available?) from amibay and fitted this in the correct orientation.

The result?  Power on and the machine sits in a reboot loop with the power/filter LED cycling between dim/bright.

Should I have to do anything else?  Would a dead FPU cause the behaviour?  Is this likely to be due to overclocking the 40MHz FPU to 50MHz?  Anything else I can try?

I've now removed the FPU and the machine is again booting as normal.

I'm really hoping I've not wasted £20 on a dead FPU.  This is after wasting £25 on a 33MHz FPU I somehow bid on mistakenly believing it to be a 40MHz part.  At this rate I may as well have put the money towards a 68040 card ...


Steve

[matt020]

Clocking a 40mhz FPU at 50mhz should be fine.
 
Have you tried seating and re-seating it a few times? Could it be a bad install the first time?

[TCMSLP]

I've tried several times, mostly the machine just refuses to boot.  A couple of times it's booted but SysInfo doesn't show any FPU present (I figured the FPU wasn't seated properly).

[DonutKing]

I've had a similar problems with my Phoenix 1000 board. With FPU installed I get flashing power LED and black-grey-white screen in a loop.
Unfortunately I'm yet to acquire another FPU to test and I don't have anything else to try the FPU in, so I don't know if the FPU is dodgy or something else is at fault.

Seeing someone else with similar symptoms on different hardware though, makes me think that maybe we both have dodgy FPU's as that's the only common thing between them.

And personally I'd try running it at stock speed until you can discount the overclocking as the source of the problem - if your clock crystal is socketed I'd pick up a 40MHz or 33MHz one from the  local electronics shop, swap it over and see if that makes any difference (or if the 33MHz FPU works too).