Common A1200/4000 deaths, CIA chip

[Plaz]

I haven't repaired amigas as a service in several years, but while I did the surface mount CIA chips were a common cause of failure. Matter of fact, CIA chips have always been a failure point for Amigas, no matter the model.

Replacements for the older socket versions can be had by stripping an old dead A500 typically. Supplies for the surface mount versions in the 1200/4000 seem more scarce. I've read multiple post lately concerning or including references to dead 1200's and it had me thinking if many could be easily repaired with a new CIA.

With all the other work being done to emulate classics using FPGA technology, could it be possible to make an affordable replacement for a dead CIA? Or does enough documentation exist to make a new source of CIA's using another PCCL chip?

Plaz

[Plaz]

@amigaksi

That a nice cable to work around dead amiga floppies or a crippled CIA chip. But some CIA chips die so hard, they keep your amiga from booting at all.

I found that the CIA chip behaves differently on these two machines; I can't seem to program the SIDE, DIR, and STEP pins on the CIA chips on the Amiga 4000 for input mode while I can do that on the Amiga 1200.

That's interesting. I would think they would be identical. Some one with the right documentation could probably answer this. Dave Haynie are you there? :-)

Plaz

[Plaz]

Cheapest way is using cia from another half dead board

Yes, but the point is to repair the half dead system.

Plaz