I last did this - 5 minutes ago :-
http://www.facebook.com/photo.php?pid=14975080&l=c77753faff&id=546790172
Still disappointed by the overheating A1200 causing graphics corruption and random crashes. Is it the caps? Most seem to be tantalum (?) anyway - only 3 elctrolytics on the board. I've now removed the metal shielding to enable better airflow ... and still it crashes when hot 
You shouldn't be experiencing an overheating A1200 unless maybe you have an 040 card and/or a bunch of other power hungry or heat producing internal goodies. Indivision ECS maybe? Get yourself a tiny/silent fan or two, the kind made for processors, to put in there and see if that helps. Easy to mount those little fans either on top of the case by the vents or underneath them, inside the case.
When I had an Indivision AGA, it would get real hot and eventually start producing random lines on the screen. And yeah, sometimes the computer would crash. This was with an A500 supply, 030 card and a 2.5" HD. I placed a single little fan on top of the case, blowing into the machine and it was much, much happier
Have you got a bunch of internal peripherals and are using a stock A1200 power supply? If so, you might want to get yourself an A500 supply or a modded modern PC supply with an adapter.