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You won't get hurt working on a live computer unless your power supply is dangerously engineered (stick to well known named brands) or wide open (don't open it

You won't get hurt working on a live computer unless your power supply is dangerously engineered (stick to well known named brands) or wide open (don't open it up unless it's been unplugged and sitting on a shelf for months) for the same reasons pointed out elsewhere in these comments; the voltage simply isn't high enough. It won't even induce a perceptible amount of current (unless you do something stupid like stick your tongue on it), much less a harmful amount. You'd be surprised at all the stuff you can get away with on a live computer. For example, did you know that AHCI (SATA) and PCIe (and thus NVMe) are both hot-pluggable and hot-swappable? ... and that you can hotswap RAM (with a cooperating motherboard and OS) and even CPUs (on multi-socket boards)?

fendy3002 4y ago
Hdd or ssd are hot swappable? thats cool, thanks for sharing. as for ram I have tried it once and it freeze the pc, I forgot if I have another plugged in or not though.
- SV_BubbleTime 4y ago
  Sata is hotswappable. IDE was not. And I believe m.2 would be if the connector was designed a little different, because that’s all u.2 is. Compact Flash Express is, but again, that’s NVMe and splitting hairs between u.2. Typically on hot swappable devices it’s been common to make the ground pins a little longer than the rest, ensuring that those will make contact first. The issue with hot swappable devices aside from a sharp initial draw is “grounding” the circuit to an IO pin before real ground is made. Most default low potential IO pins won’t enjoy taking the full load of the device while the ground plane is missing connection. Oddly to me, many new PC BIOS ship with SATA hot swapping disabled. IDK why. You can plug the drive in it’ll spin up, but no data transfer will happen until you reboot. Safe, just ineffective. I recently had to learn this the hard way.
  - Nextgrid 4y ago
    > no data transfer will happen until you reboot I think this is something the OS can override. If I remember correctly I could discover a hotplugged SATA device in Windows by using "Scan for new hardware" in the Device Manager.
    - aaronmdjones 4y ago
      More specifically, the system's firmware AHCI hotplugging configuration only applies to the system firmware. That is to say, if hotplugging is disabled on your SATA controller, then the firmware won't see a new SATA drive if you plug it in while the machine is running. So, for example, you won't get a UEFI boot menu entry for it if you go to the boot override section that presents all of your storage devices. Once the operating system takes over, that's all a moot point. Whether hot-plugging was disabled in your firmware settings or not, if the OS supports it, it will work. Both Microsoft's AHCI driver (msahci.sys) and the Linux "ahci" kernel module (or built-in) support hot-plugging. On my Windows desktop with an Intel SATA chipset, hot-plugging a drive did cause Windows to briefly drop all other drives on that controller before re-enumerating all of them, which lead to a BSoD because one of those drives was the drive with Windows itself on it. However, this was solved by installing Intel's chipset-specific driver (Intel Rapid Storage Technology, iaStorV.sys) and tweaking the registry to have that one start at early boot instead of msahci.

fendy3002 4y ago

Hdd or ssd are hot swappable? thats cool, thanks for sharing. as for ram I have tried it once and it freeze the pc, I forgot if I have another plugged in or not though.

SV_BubbleTime 4y ago
Sata is hotswappable. IDE was not. And I believe m.2 would be if the connector was designed a little different, because that’s all u.2 is. Compact Flash Express is, but again, that’s NVMe and splitting hairs between u.2. Typically on hot swappable devices it’s been common to make the ground pins a little longer than the rest, ensuring that those will make contact first. The issue with hot swappable devices aside from a sharp initial draw is “grounding” the circuit to an IO pin before real ground is made. Most default low potential IO pins won’t enjoy taking the full load of the device while the ground plane is missing connection. Oddly to me, many new PC BIOS ship with SATA hot swapping disabled. IDK why. You can plug the drive in it’ll spin up, but no data transfer will happen until you reboot. Safe, just ineffective. I recently had to learn this the hard way.
- Nextgrid 4y ago
  > no data transfer will happen until you reboot I think this is something the OS can override. If I remember correctly I could discover a hotplugged SATA device in Windows by using "Scan for new hardware" in the Device Manager.
  - aaronmdjones 4y ago
    More specifically, the system's firmware AHCI hotplugging configuration only applies to the system firmware. That is to say, if hotplugging is disabled on your SATA controller, then the firmware won't see a new SATA drive if you plug it in while the machine is running. So, for example, you won't get a UEFI boot menu entry for it if you go to the boot override section that presents all of your storage devices. Once the operating system takes over, that's all a moot point. Whether hot-plugging was disabled in your firmware settings or not, if the OS supports it, it will work. Both Microsoft's AHCI driver (msahci.sys) and the Linux "ahci" kernel module (or built-in) support hot-plugging. On my Windows desktop with an Intel SATA chipset, hot-plugging a drive did cause Windows to briefly drop all other drives on that controller before re-enumerating all of them, which lead to a BSoD because one of those drives was the drive with Windows itself on it. However, this was solved by installing Intel's chipset-specific driver (Intel Rapid Storage Technology, iaStorV.sys) and tweaking the registry to have that one start at early boot instead of msahci.