macgyver84
New member
Hi,
for over a decade, I have owned a spare IIfx logic board (bare board, not in a case). Seems like it had not been worked on before, original (electrolytic!) caps. It chimed, but did not show any video and did not boot. A recap with tantalums and a thourugh board wash has changed nothing back then, so it sat in the closet for years.
I decided to give it another go now, however I haven't had any success yet. I have another working IIfx and tried the board with its RAM modules and the ROM SIMM, good known graphics card and PSU, so the fault must be definitely with the board. The PCB is looking pretty good with only minimal signs of corrosion on some traces/vias. All of them turned out to be fine when scraped/measured. I already checked lots and lots of traces and vias, have also removed ICs near caps to look under them, so far I have not found anything wrong - there was no need to repair any trace yet, so no smoking gun so far.
In detail, when I turn the power on (power circuit works fine), it immediately gives the "good" chime, then after maybe 2...3 seconds delay there is a faint "pop" in the speaker, then nothing. No video, no nothing. Pushing the interrupt button will give the death chime, other than that I failed to get any reaction out of this board. No try to boot from floppy, no ejecting a non bootable floppy, nothing.
Are there any "common" faults associated with that on the IIfx? Any ICs I might try to remove, like the SWIM chip, any other hints like common bad traces I might have overlooked? I feel like it is almost working and hate to give up. It is possible that this board was removed from a computer a long time ago and might have died of other causes than leaking caps...
Thanks a lot!
for over a decade, I have owned a spare IIfx logic board (bare board, not in a case). Seems like it had not been worked on before, original (electrolytic!) caps. It chimed, but did not show any video and did not boot. A recap with tantalums and a thourugh board wash has changed nothing back then, so it sat in the closet for years.
I decided to give it another go now, however I haven't had any success yet. I have another working IIfx and tried the board with its RAM modules and the ROM SIMM, good known graphics card and PSU, so the fault must be definitely with the board. The PCB is looking pretty good with only minimal signs of corrosion on some traces/vias. All of them turned out to be fine when scraped/measured. I already checked lots and lots of traces and vias, have also removed ICs near caps to look under them, so far I have not found anything wrong - there was no need to repair any trace yet, so no smoking gun so far.
In detail, when I turn the power on (power circuit works fine), it immediately gives the "good" chime, then after maybe 2...3 seconds delay there is a faint "pop" in the speaker, then nothing. No video, no nothing. Pushing the interrupt button will give the death chime, other than that I failed to get any reaction out of this board. No try to boot from floppy, no ejecting a non bootable floppy, nothing.
Are there any "common" faults associated with that on the IIfx? Any ICs I might try to remove, like the SWIM chip, any other hints like common bad traces I might have overlooked? I feel like it is almost working and hate to give up. It is possible that this board was removed from a computer a long time ago and might have died of other causes than leaking caps...
Thanks a lot!