Quick question after a re-cap. Everything seems to be working fine except two oddities.
1. When I replaced the caps, I also replaced the two 220uf 250v capacitors. The kit I got had two very large versions of this capacitor. The values were correct, but they were a little hard to get into that space. Anyway, when I was done and powered everything on, the computer chimed and started (I didn't have the monitor on, but could hear the drive booting). But then, I saw smoke from one of those 250v caps and the top of it started to crinkle and melt, so I pulled the power. After a few seconds, I touched both caps and only that one was still super hot. Yes, the polarity was correct. So I pulled both caps and replaced them with an older kit I had from last year. These seemed to work and I sat and watched for about five minutes... nothing bad was happening. Then I did something stupid; I touched the top of the cap that previously had the melting/smoking cap to see if it was hot. I got the shit zapped out of me. Felt like 120... so, I get to my question; is it normal to be zapped by the metal top of a capacitor? I thought it was ground. I will add two other things; that triangle shaped thing that screws to the side of the power supply cage was not attached yet (I assumed it was for thermal purposes, not grounding as all the grounding was coming from the screw by the power connections and the board screw locations) and I may have also touched the thick metal cage thing that surrounds those capacitors at the same time.
2. So, everything seems to work fine now even though I wonder about the cap zapping me. However, I don't recall the back power switch on the Macintosh resetting the computer, I thought it powered it off - forcefully. When I push it now, it shuts off the computer (forcefully), but immediately, the computer turns back on. The keyboard power button works just fine - turning it on and suggesting a shutdown option if pressed while the computer is running. Is that the normal behavior for that back button; Apple documentation seems to suggest otherwise. If not, any ideas on what could be causing the behavior? (the daughterboard cap replacement?)
Thanks All!
-Christopher
1. When I replaced the caps, I also replaced the two 220uf 250v capacitors. The kit I got had two very large versions of this capacitor. The values were correct, but they were a little hard to get into that space. Anyway, when I was done and powered everything on, the computer chimed and started (I didn't have the monitor on, but could hear the drive booting). But then, I saw smoke from one of those 250v caps and the top of it started to crinkle and melt, so I pulled the power. After a few seconds, I touched both caps and only that one was still super hot. Yes, the polarity was correct. So I pulled both caps and replaced them with an older kit I had from last year. These seemed to work and I sat and watched for about five minutes... nothing bad was happening. Then I did something stupid; I touched the top of the cap that previously had the melting/smoking cap to see if it was hot. I got the shit zapped out of me. Felt like 120... so, I get to my question; is it normal to be zapped by the metal top of a capacitor? I thought it was ground. I will add two other things; that triangle shaped thing that screws to the side of the power supply cage was not attached yet (I assumed it was for thermal purposes, not grounding as all the grounding was coming from the screw by the power connections and the board screw locations) and I may have also touched the thick metal cage thing that surrounds those capacitors at the same time.
2. So, everything seems to work fine now even though I wonder about the cap zapping me. However, I don't recall the back power switch on the Macintosh resetting the computer, I thought it powered it off - forcefully. When I push it now, it shuts off the computer (forcefully), but immediately, the computer turns back on. The keyboard power button works just fine - turning it on and suggesting a shutdown option if pressed while the computer is running. Is that the normal behavior for that back button; Apple documentation seems to suggest otherwise. If not, any ideas on what could be causing the behavior? (the daughterboard cap replacement?)
Thanks All!
-Christopher
Last edited:
