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2010 iMac dismantle and electrocution
- Thread starter zoran
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'Electricution' has been an anti-repair scare warning ever since iMacs switched from CRTs to flat displays. The last person who told me that with a straight face was an Apple 'genius' who was horrified/impressed that I had opened my own 2011 iMac.
That said the power supplies do have capacitors large enough to deliver a shock. That could arc through jewlrey into other sensitive components or prompt a reflexive jerk which might have unfortunate results depending on your surroundings.
It is considered best practice to press and hold the power button after unplugging the iMac to drain capacitors. Bonus points for proper ESD handling.
That said the power supplies do have capacitors large enough to deliver a shock. That could arc through jewlrey into other sensitive components or prompt a reflexive jerk which might have unfortunate results depending on your surroundings.
It is considered best practice to press and hold the power button after unplugging the iMac to drain capacitors. Bonus points for proper ESD handling.
Is this documented somewhere? For how long must the powerbutton be pressed for full drainage?
General best practice for any electronic device. Some people say 10s, others 30s. See: https://www.beyourownit.com/computer-repair-safety/
Tip: Don't assume full drainage. Give the power supply a little extra care and respect when you get to that part.
I remember the lessons I learnt in audio amplifier repairing class.
- The first thing you do after opening an amplifier (unplugged, of course) is to short out all big capacitors. Failing to do so might cause fire sparks which could destroy your precious components, get yourself burnt, or worse, cause fire to your workplace.
Charged capacitors are very dangerous.
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You could get electrical shocks from the power supply as well as the display inverter but as long as you don't touch any components directly you should be safe.
The other way around static energy however can seriously damage components in your iMac.
But if you touch grounded appliances like a radiator before it should be fine.
The other way around static energy however can seriously damage components in your iMac.
But if you touch grounded appliances like a radiator before it should be fine.
I've never thought that a grounding strap would protect ME. I was under the impression it was to protect the components.
One time I was replacing some electrical component on my car (alternator I think). Whatever it was required the disconnection of the battery.
I had my gold wedding band on at the time.
At some point, the wrench I had left on top of the battery managed to make some sort of connection. I was entirely unaware of this until my wedding band got intensely hot. So, I look up and there's the wrench having bridged itself while I'm working on metal parts inside the engine compartment.
I immediately took my ring off and dislodged the wrench. The only lasting result was that I managed to make the inscription on my ring darker because I inadvertently had driven current through the ring.
You know how they say gold is a great electrical conductor? Well, yeah!
I have disassembled multiple iMacs to the ground (last one was my 5K iMac 2017) and never really put too much thought into the possible hazards of handling the power supply. What I did make sure of however was to only handle the power supply by the edge of the PCB and not too touch the components (especially not the capacitors). I do that btw with every circuit board (i.e. not touching the components on the board unless it is necessary or unpreventable). I also do not wear an ESD wrist strap anymore because it is annoying (I know, it is a pretty bad excuse). My anti-static precautions do include touching a ground (like the chassis of a Mac Pro that is plugged into an outlet) from time to time to get rid of potential static electricity. When you do handle the power supply by the edge there shouldn't be a problem. I have yet to get shocked (hopefully not 😅). All in all, I'd say the risk of electrocution is pretty low.