I don't recommend using a vacuum on the inside of the case because most motherboard have electrical jumpers that can be sucked off.
I have never experienced that but I can see how that is possible with jumpers that are worn and/or have lost their clamping tension. However, the greater concern with using a vacuum inside the case is destruction from
ESD. As the dust and air particles zoom past and crash into the nozzle end (especially with plastic nozzles) extremely high potentials of static electricity can build up in the nozzle. And when the nozzle comes in to close proximity to ESD sensitive devices, such as the CPU, memory modules and other high density integrated circuits (ICs or "chips), that static can easily be discharged through the device, totally destroying it - often without the user even knowing a discharge occurred.
For these reasons, vacuuming is NEVER preferred. Taking the computer outside is always better. If it is pouring down rain, and taking it outside is not practical, you can use a vacuum, but EXTRA care must be taken.
- Unplug the computer from the wall.
- Touch bare metal of the case to discharge any static in your body, and most importantly, to put you and the computer "at the same potential".
- Wrap your hand around the nozzle end and extend a pointed finger out to plant it on bare metal when reaching in with the nozzle to prevent the discharge and build-up of static.
- Use a soft, natural bristle (not synthetic) paint brush to gently persuade the dust to the nozzle.
- Better yet, wait for it to stop raining.
Note I use an air compressor and a soft, natural bristle paint brush in (or rather, outside) my shop to blast out electronics all the time. HOWEVER - there are special considerations that MUST be adhered to when using an air compressor on electronics.
- The compressing process WILL create condensation inside the tank. This condensation collects on the walls of the tank, then runs down to the bottom. If allowed to build up, water particles can be spewed onto the electronics - never good. So periodic draining is required and all air compressors have a pitcock valve for this purpose.
- Ensure the compressor is an "oil-less" type.
- I prefer upright compressors to keep any condensation way down at the bottom.
- ALWAYS - as in EVERY SINGLE TIME - use a inline moisture and particulate filter.
- Never see how fast you can make a fan spin - you can easily exceed design limits and destroy the bearings (I use wooden glue/Popsicle sticks to hold the blades stationary).
- Most compressors can deliver 90-120PSI. Toggle down to 80PSI when blasting dust from electronic.
Note that cans of dusting gas will do in a pinch, but note it is not canned "
air". It typically consists of toxic difluoroethane and should not be inhaled.
Finally, make sure any case you buy in the future has a removable, washable air filter. These, as a minimum, cut in half the number of times you need to clean out the interior.