Introduction
Step 1: Creating a bootable memory stick
Step 2: Creating a service tool battery
Step 3: Flashing the firmware
Conclusion
Now that we have a bootable memory stick created containing the service utilities and the custom firmware, we need to get the PSP to boot off the memory stick. Under normal circumstances, the PSP will always boot from the firmware image stored its embedded flash memory. By booting from our freshly created magic memory stick, we can replace the contents of the PSP’s embedded flash memory with the custom firmware image.
To make the PSP boot from the memory stick is very simple, we need to tell the PSP to enter service mode. Sony created a service mode for the PSP that allows a technician to boot from a secondary device and run service utilities on defective or damaged PSPs. One example might be if a PSP no longer turns on, a technician would be able to diagnose and replace a damaged firmware through these service utilities – very similar to the goal of this HOWTO. This service mode is accessed by using a service tool battery – sometimes referred to as a Pandora or Jigkick battery. When this type of battery is inserted in to the PSP, the PSP recognizes it and the function of booting from the memory stick becomes available. Since Sony does not make these service tool batteries available to consumers, it is possible to create our own service tool battery from the battery that comes with the PSP slim.
My best understanding of how it works is that each PSP battery has a unique serial number programmed in to the battery’s EEPROM which is checked when the battery is inserted in to the PSP. If a normal battery is inserted, the serial number is checked and the PSP operates as normal. The difference is a service battery has a serial number of all 1s. When inserting the service battery, the PSP will recognize the serial number of all 1s and allow booting from the memory stick.
Although there are different methods of creating a service tool battery, I will only focus on the “hard-mod” method. Through this method, we will be making a physical change to the battery itself. Although this step is not overly difficult, it is a bit challenging. If you decide to attempt this procedure, please use extreme care. Work in a clean and well lit area. Exercise care and patience. Make sure you full understand this tutorial and the risks associated with it. I am not responsible for any damages caused by this tutorial.
We will need the following items to complete this step:
PSP Slim battery model PSP-S110 (3.6V 1200mAh)
Guitar pick
Magnifying glass
Sharp utility knife
Packing tape
Step 1: Prepare your work area. Always have a clean and well lit area to work with. It is a small step that is often overlooked. Have your required tools listed above ready to work with. Prepare yourself for about 20 minutes of work. When you are ready, open the battery door of your PSP and remove the battery.

Step 2: Open the battery case using a guitar pick. Although a small screwdriver or utility knife might work well too, I like the simplicity of a standard guitar pick. The guitar pick is sturdy, has very thin rounded off edges with a nicely rounded off point. The guitar pick has a very small chance of doing any permanent damage to the PSP whereas a metal tool can do more damage to the battery’s plastic shell or even worse, permanently damage the small circuit board inside the battery beyond repair. Note that the pick I used had a small crack in it before opening up the battery.
This step only requires some time and patience. It is really quite easy.

First, gently slide the guitar pick in to the left and right sides of the battery where the two halves of the plastic shell meet. Work it in slowly and you should feel the pick getting between the halves. Slowly work your way up and down the groove and you will feel and hear the seals snap.
Repeat this for the bottom of the battery. Work the guitar pick in to the bottom seam and slow and gently break the seal. The corners can be a bit trick but just work slowly and be gentle. I cannot stress enough to take your time and be patient during this procedure.
Once the two sides and bottom have been unsealed, we only need to complete the top of the battery to remove the casing. The top of the battery is a bit harder in the area where the battery terminals connect to the PSP. As always, just work slowly and be gentle and you may need to apply some mild pressure to physically separate both pieces of the battery shell.
Step 3: Now that the battery case has been opened, you will see a small circuit board attached to the still-sealed Lithium-ion battery by two small piece of metallic foil. Gently unfold the circuit board away from the battery pack and lay out flat. Notice in the following picture the red circle around the number 19 on the circuit board. In this case, 19 is the magic number.


Step 4: Cut the number 19 trace. Using a magnifying glass and well lit area will make this a easier. Hold the battery and circuit board securely and very still. Using a very sharp utility knife and some pressure, make a good and deep cut right through the number 19 trace wire. This will damage the circuit board in a way that the EEPROM will report the serial number as all 1s.

Step 5: Close the battery back up. Fold the circuit board back in to place and re-assemble the plastic battery shell. Since the battery shell will not stay closed on its own anymore, use some small pieces of packing tape to hold the shell firmly together. Put a piece of tape on the sides with some extra attention to the top of the battery. This is due to how the battery requires a little upward force when removed from the PSP. I like packing tape since it is very thin and strong. Other tapes are thicker which might cause the battery to get stuck inside the battery compartment. Packing tape can also be removed easily if you need to repeat step 4 in the event that it didn’t work – or just to show your friends.

If you have completed these steps successfully, the PSP power will automatically power on when the battery is inserted. The screen will likely remain black but the green power light should come on. If the power does not automatically come on, try manually turning the PSP on to make sure the battery has not been permanently damaged. If you get no power at all, you better go buy a new battery. If you do get power, then chances are you did not cut trace 19 completely. Repeat steps 4 & 5 until you can insert the battery and the power light automatically comes on. It took me two tries to get it right so don’t worry or rush yourself.
Remove the battery from the PSP and leave it off to the side for now. Now that we have a service tool battery and bootable memory card ready for use. In the next step, we will use these two tools together for bringing new and wonderous functionality to our PSP.
On to step 3…