How long did your old computers last before they died?

[Ilwrath]

It's a complete scatter for me.   Here's a rundown of my primary systems and their demise (or lack thereof)

My first "computer" was a Bally Astrocade from my uncle.  (it had a basic cartridge, too.)  It still works great, and I just played some Wizard of Wor (Incredible Wizard, it's called on there, but anyhow...) a few months ago.

My first C64 lasted two or three years before the power supply fried itself and damaged the board to a point it was cheaper to buy a new one.  

My C64C then lasted a couple years before it developed some odd random reset quirks, but by then it was old enough I sold it and my whole lot of C64 stuff to buy an Amiga 500.

My Amiga 500 was perfect.  Never a glitch over the 3-4 years I had it.  Sold it to buy an A1200.

My first A1200 was perfect for about a year before it developed the "A1200 AGA graphics fringe" bug (overheating Alice, but no one knew that at the time).  I got it replaced under warranty just before C= went under.  Second A1200 developed same issue a year later.  Picked up a used A4000.

My A4000 was my primary system for about 4-5 years, until I retired it.  It has stayed put for retro purposes.  About two years ago, the CyberStorm MKII I put in it back when I was using it as my primary, finally gave up.  It's not really dead, as eventually I'll send it to AmigaCenter for repairs.  Currently, it occupies a shelf, though.

I built an Athlon T-bird 1ghz which overtook the A4000 as my primary machine.  It ran until about 4 years ago when the motherboard fried.  I sold the CPU to an Amiga.org member.  Gave the RAM to a friend and folded the rest into my current workstation.

I built a P4c 3ghz that has been in use for about 4 years now.  Still going strong.

[Ilwrath]

[A1200 "fringing"...]I've never heard of this problem before, is it a common problem with a1200's?, does it affect a4000's?

It's fairly common with at least one or two of the earliest revisions of A1200.  I've personally owned 2 over the years that have had it in some varying degree of severity.  Some develop it worse than others.  (The worst one I've seen was the A1200 I purchased new shortly after they came out -- the one Commodore replaced.)  It's much more likely to occur in productivity screen modes.  Also, I've found it more likely to show up in accelerated machines.  (Also lending validity to the explanation I've heard that it is caused by Alice overheating.)

As far as I know, it's isolated to the A1200.  I've never seen an A4000 do it.

In another thread I think alexh said heatsinks should not be put on plastic packaged IC's, but should I put heatsinks on all my alice chips anyway?

Hmm...  I'm not really sure.   I might question how much a heatsink would help a plastic-packaged IC, but I doubt it would hurt it.  A quick search on Google only turned up articles about the problems of heatsinks on plastic-packaged ICs in a BGA application.  (Apparently, the temperature difference across the chip package can cause solder-ball problems -- that was news to me.)  Anyhow, that would seem unlikely to be an issue for the more conventional PLCC-style A1200 chips.

Are there any other known issues which I do not know about, is there a list somewhere?

 There are always a few "gotchas" for any Amiga model.  Other than Warren Block's site for the A3000 and A4000, I don't know of any other such resources.  

I've pondered making a "Known Amiga Hardware Usage" catalog, myself...  Essentially just a system to provide an easily searchable assembly of users notes on the old hardware.