If you're aiming to get your hands on the most powerful weapons and wipe out the zombie hordes with ease, you need to know that many of the most effective weapons can only be obtained once they've been upgraded using the Pack-a-Punch machine.
Steps

Build the Turbine at the Bus Station. Gather all the necessary parts and assemble them at the Workbench. You’ll need at least one part (or two). It's a good idea to have another player carry one part just in case things go wrong.
- The battery is located near the phone booth.
- The mannequin can be found next to the map board.
- The fan is placed on one of the waiting area seats.

Pick it up and leave. You can either take the bus to the power station or teleport directly there.

Open the door to the power station (costs 750 points). Activate the power (this step can be skipped).

If the power is on, place the Turbine in front of the lobby where you initially dropped down. Leave the area and head straight to the town.

If the power is off, don't go below. Place the Turbine in front of the door leading down, within close proximity. Once done, head towards the town.

Open the bank in the town. Then, you will need to unlock the vault. If the Turbine is still running, the vault will open.

Search for the parts. You need to find the board, slot, and battery. These items are scattered around the vault area.

Assemble the parts at the Workbench located behind the vault area. The end result will be the Pack-A-Punch machine.

Use the Pack-A-Punch machine on one or more of your weapons (costs 5000 points). The power of your weapons will be enhanced, their names will change, and they will receive overall improvements.
Tips
- Different weapons will yield different results when used with the Pack-A-Punch machine.
- You can use the Pack-A-Punch machine on your weapons multiple times.
- Have another player hide behind the power station and guard the Turbine.
- You can stand at the entrance to the vault (as long as you're not standing on the stairs) and avoid zombie attacks from below.
- You are allowed to reopen the vault at any time by using a new Turbine.
- Use grenades to blow open the bank and the vault.
- To save time, you can open the door to the power station. Instead of jumping down, place the Turbine near the door to unlock it. The Turbine’s power will still affect the station and open the vault.
Warning
- If the Turbine breaks down with no one nearby, the vault will close.
- You cannot carry multiple parts at once.
Things You Need
- Xbox 360/PS3 Game Console
- TV
- Controller
- Internet
- Microphone
- Black Ops 2 Game
