Arisotura
Well-known member
As title says.
Basically, my IIfx isn't giving any sign of life, and here's what I observed so far:
UJ7, UK7, UL8 and UN9 get really hot. Not sure if that's indicative of any fault? These chips seem to be GAL16's. I'd understand why one would fail, but... all of them, at once? So I'm unsure there.
I also found that the FPU select line from the OSS is low, so I figure the computer gets stuck trying to do something with the FPU. The FPU select line goes through UL6, entering at pin 19 and coming out of pin 26 to go to the actual FPU. But, that's the thing: while pin 19 was a solid low, pin 26 was at like 3.7V, which doesn't seem right.
I desoldered UL6, wired it to a socket to put it in the Minipro and see what's inside. It reads (as a GAL20V8), but the contents are mostly just a repeating pattern of 0 0 1 1 0 0 1 1...
So: anyone got proper dumps of these GALs I can compare to? Or alternately, some replacement chip?
Basically, my IIfx isn't giving any sign of life, and here's what I observed so far:
UJ7, UK7, UL8 and UN9 get really hot. Not sure if that's indicative of any fault? These chips seem to be GAL16's. I'd understand why one would fail, but... all of them, at once? So I'm unsure there.
I also found that the FPU select line from the OSS is low, so I figure the computer gets stuck trying to do something with the FPU. The FPU select line goes through UL6, entering at pin 19 and coming out of pin 26 to go to the actual FPU. But, that's the thing: while pin 19 was a solid low, pin 26 was at like 3.7V, which doesn't seem right.
I desoldered UL6, wired it to a socket to put it in the Minipro and see what's inside. It reads (as a GAL20V8), but the contents are mostly just a repeating pattern of 0 0 1 1 0 0 1 1...
So: anyone got proper dumps of these GALs I can compare to? Or alternately, some replacement chip?