Class about breaking PCs

[Train27]

I wasn't really sure where to post this topic, hope I chose the correct subforum.

 

Anyway, the thing is a few days ago I had a crazy fun class at my University. It was a regular day in my Computer Architecture class until the teacher arrived to the room with a big perverse smile, and proceeded to explain what we'd do that day. It was about breaking computers.

 

The group before us had mess with some old pc's and we had to repair them, find the possible errors, troubleshoot them and make them work. And then, it was our turn to break them for the next group.

Of course, by "break" I don't mean irreversibly break them, just touch a few things here and there.

 

I found the concept interesting so I decided it'd be good to share, and so I could tell what I made to the pc and also ask you: what would you have done to it?

I did the following:

• Moved the graphics card from the PCI Express x16 to the PCI Express x4 slot
• Moved one stick of RAM to another channel (nulifying double channel), and set the other one almost well introduced into the slot.
• Connected the IDE cable from one port of the motherboard to another.
• Connected the HDD to the disk drive via a sata cable.
• Completely messed with the jumpers.
• Disconnected the chipset's fan.
• Disconnected the front pannel's buttons (on/off, reset...).

 

P.S.: I attach a photo of the motherboard.

[Starelementpoke]

6 minutes ago, Train27 said:

I wasn't really sure where to post this topic, hope I chose the correct subforum.

 

Anyway, the thing is a few days ago I had a crazy fun class at my University. It was a regular day in my Computer Architecture class until the teacher arrived to the room with a big perverse smile, and proceeded to explain what we'd do that day. It was about breaking computers.

 

The group before us had mess with some old pc's and we had to repair them, find the possible errors, troubleshoot them and make them work. And then, it was our turn to break them for the next group.

Of course, by "break" I don't mean irreversibly break them, just touch a few things here and there.

 

I found the concept interesting so I decided it'd be good to share, and so I could tell what I made to the pc and also ask you: what would you have done to it?

I did the following:

• Moved the graphics card from the PCI Express x16 to the PCI Express x4 slot
• Moved one stick of RAM to another channel (nulifying double channel), and set the other one almost well introduced into the slot.
• Connected the IDE cable from one port of the motherboard to another.
• Connected the HDD to the disk drive via a sata cable.
• Completely messed with the jumpers.
• Disconnected the chipset's fan.
• Disconnected the front pannel's buttons (on/off, reset...).

 

P.S.: I attach a photo of the motherboard.

That sounds fun as fuck actually.

[Unimportant]

I'd put the clear CMOS jumper in the clear position. Most boards do nothing when powered on with that jumper in the wrong position and I'm always amazed with how few ppl find the culprit.

 

You disconnected the chipset fan -> Was it even running when connected? I remember having to RMA boatloads of early nForce4 motherboards like that one because the tiny crappy fan failed within months.

[You_are_a_cunt]

So, basically my computer retirement ritual?

I do that with PCs that are unsellable, outdated to the point of uselessness and broken in ways that require black magics to fix

[Huntsman]

When out of ideas.. there's always the USB Killer

[klh2000]

2 hours ago, Huntsman said:

When out of ideas.. there's always the USB Killer

I made on of those, but it isn't nearly as streamlined as the one they sell. I have an old IBM mouse with 350uF worth of caps charged up to 300v. It will fire the caps when you press the middle click/scroll wheel . It has a dip switch to select the data lines or 5v line. It makes a loud bang when the caps fire

 

 

 

 

[corrado33]

On 11/2/2016 at 7:38 PM, Train27 said:

 

• Moved the graphics card from the PCI Express x16 to the PCI Express x4 slot
• Moved one stick of RAM to another channel (nulifying double channel), and set the other one almost well introduced into the slot.
• Connected the IDE cable from one port of the motherboard to another.
• Connected the HDD to the disk drive via a sata cable.
• Completely messed with the jumpers.
• Disconnected the chipset's fan.
• Disconnected the front pannel's buttons (on/off, reset...).

 

First one would have done nothing. It'd still work fine. (Albiet with less performance.)

 

Second one would have done nothing, except to slow it down. The non-seated ram could cause problems. But in reality, probably not. The computer would probably just ignore it.

 

Third one probably would have done nothing. You'd be essentially connecting +5V to +5V and Gnd to Gnd, the only thing that's switched would probably be the Tx and Rx lines, which wouldn't cause a problem. Bios may throw a fit trying to identify what's on the other end.

 

4th would have done nothing.

 

5th probably would have stopped the computer from booting, assuming the HDD was plugged into the MOBO, which it wasn't.

 

6th Would have eventually killed the CPU. But the bios would throw an error before you booted unless it was specifically turned off (doubtful)

 

7th Would have prevented a casual observer from making the computer start.

 

 

So really all you did was disconnect the on/off switch, preventing booting by disconnecting the HDD, and killed the CPU if the person fixed the previous two. But who in their right mind would not check everything else after they found the first 2?

 

If I wanted to "break" a modernish computer, I'd go into the bios and change the AHCI setting to IDE or visa versa. Or set the OCing to something ridiculously (low) so that the computer would refuse to boot. That usually screws things up. Then change the boot order to include floppy drives, etc. Hell, you could stick one of those tiny USB drives in the back of the computer and set the bios to boot to it, then just have it have a troll page when it fires up whatever OS you have on it. 

 

In terms of hardware, I'd purposely cut the green wire on the 24 pin so that the PS would never turn on. 

 

Alternatively you could plug the HDD into a non-bootable SATA port (yes those exist.)

 

Other alternatively is you could unplug the CPU 4 pin. Never tried this one myself, but it sure as heck wouldn't boot.

 

 

[mariushm]

Put some nail polish or some scotch tape on just one of the DATA contacts in the sata connector. You're simulating oxidation from humidity in the sata cable contacts.
Blocking just one or a couple of contacts may allow the hard drive to be detected and show up in bios but not actually be able to use it.

Move the power wire pair and on/off leds and hdd leds so that only one pin is inserted in the headers, basically simulate someone not inserting things properly. They still look like they're connected properly from far away but only when you get close you see they don't sit right.

clear cmos jumper is always a good idea

On the meaner side of things, loosen/break/disconnect the 5v stand-by wire in the 24 pin atx connector this way the chipset on the motherboard doesn't get juice so the on/off button on case won't work, the system won't boot.

 

Another option (with some slight potential of damaging things so be careful with this) .. plug both keyboard and mouse in the same group of usb connectors (they're usually sets of 4) because each set of connectors usually has a resettable fuse that triggers at around 2A ... so you could get a usb cable extension and hack it to short the v wire to ground. When user turns on the pc, after a few seconds the short would trigger the fuse and the ports are disabled so keyboard and mouse won't work. When pc is off, the fuse heals itself in a few seconds 

Though, if the usb ports are powered from 5v stand-by you can damage the power supply by pulling more than 1a from it with the short - if the psu is low end, it could damage the 5v standby circuit in the psu. Also sometimes ,that resettable fuse simply won't reset and then your four ports would be damaged for good (until your replace the fuse)

[Train27]

Dafuq the class was about making computers not working or not working properly, not about breaking them, so no nail-polish, no cutting cables and ofc no melting anything

 

Forgot to say that the BIOS battery was dead, so no point in setting the jumpers to clear (tho I thought about that) or messing with the OC or booting options.

My bad

 

The challenge was about restoring the pc to its original state, not just making it boot, thus the non-critical changes that I made (IDE cables, ram slots...).

 

Anyhow, glad to see so much participation, lots of things I didn't think of in the first place