Home▸ Forums▸ 68kMLA▸ LC475 -replaced 68LC40 for 68040 CPU — #9 Post #9 by philallin Source Forum68kMLA Category68k Post DateSun, 18 Jan 2009 - 21:38 Original URLhttps://68kmla.org/bb/threads/lc475-replaced-68lc40-for-68040-cpu.16182/ Post If you can leave your finger on the CPU indefinitely, then it's definitely running fine. If you can't bear to touch it for more than a couple of seconds, you want a heatsink. Click to expand... A good rule of thumb. :b&w: Click to expand... Surely that should be 'Good rule of finger'!! ;D