Pineconeattack!

I’ve searched and searched everywhere and I just could not find any simple precise walkthrough WITH pictures. Hopefully, I will remedy this minor oversight and help out anyone who is willing to risk this simple procedure by writing my own instructions and archive with pictures, my attempt to replacing the battery to my Phantasy Star cart. This will be a step-by-step instruction on how to change the battery inside a Sega Master System game cartridge. The reason for me to do a Sega Master game is that there only a small handful of games on this system that require batteries and you don’t need a special security bit to open this cart; a common Phillips screwdriver is all you will need to do it.

I’ve placed an order for security bits and they should arrive later this week, but for all intents and purpose, this battery replacement walk-through should be universal and can be applied to Super Nintendo, Genesis, and N64 carts. I will be doing some more walkthroughs in the near future so that cautious gamers wanting a step-by-step guides for their specific game console will have it.

It may seem a bit redundant but I know I would not have minded to have some redundant instruction on how to swap out batteries, anything to ease my fears of accidentally destroying a valuable game. This was my first attempt at a battery swap and I just wanted to show everyone how easy it can be. There are several walkthroughs online that require you to take an X-acto knife and break off the weld that connects the tabs to the battery. Being from the electronics field, I personally feel this method to be shoddy approach and can cause damage to yourself and game. Though I don’t agree with this method, you can follow the instructions at the Cheapassgamer forums or head over to Racketboy for such instructions.

My belief is that the only proper way of replacing a battery is to unsolder the old battery and resolder a new one. This is how the game was assembled from factory and I feel this is how the battery should be replaced. You will need to have some basic soldering skills to complete this task. This walk-through can be applied to any gaming cart that requires a small button 3V battery (with 2 pin leads), but because I can’t be sure of your soldering abilities and there is a potential risk since you are applying heat to a battery, I cannot be held responsible if you damage your game or hurt yourself. I repeat: I will not be held reliable for any bodily damage or damage that is done to your property.

Read here if you want to learn basic soldering. Soldering is a fun and simple hobby but if you are lacking the confidence to replace the battery, please seek out a local video games repair store near you and have a professional replace the battery.

One final note: you will lose your saves when you replace the save battery. There is no real easy way to avoid this problem. Yes there are complicated methods like adding a slave battery but I just find this method to be cumbersome and not worth the extra risk. With that out of the way, here is what you will need to replace a battery in a Sega Master System cart.

ITEM LIST:

• Soldering Iron- I paid about $100 for my Weller soldering iron because the Weller soldering irons are grounded to the tip so there is less of a risk of shorting out your PCB.

• Cr-2032 button battery WITH 2 pin leads attached. The battery is used for this project is a CR2032-2-15 which can be found for $2.50 here.

[UPDATE: The battery that I found to be the best is the CR2032-T. There is no cutting or any other type of modifying. Best battery yet!]

• Electrical Solder
• Protective goggles
• Solder Sucker
• Diagonal Cutting Pliers
• Screwdrivers
• Electrical Tape (optional)
• Plenty of room to work.

Step 1: Flip over the cart and remove the 2 screws. Remove the back cover the just flip it over so the back cover is now facing down on the table.

As you can see the battery is soldered onto the PCB by two points.

Please make note where the positive and the negative leads are located on the board.

If you look real closely, the polarity is marked on the board in case you forget.

Step 2: Apply the soldering iron to one of the battery terminal. Let the iron transfer the heat to the pin rather than touching the iron to the solder itself. You will notice the solder will begin to melt. Put the solder sucker up to it and press down to suck up the melted solder. Repeat until the majority of the solder has been removed from both leads.

Step 3: With the majority of the solder removed, gently wiggle the battery lose from the PCB. If the battery won’t budge, remove some more solder and try again. DO NOT RIP THE BATTERY OFF THE BOARD. You can damage the game if you are not gentle.

Once the battery is removed, you should see the slots where the new battery will be placed. Your battery is now free from the PCB.

Step 4: Insert the battery onto the PCB. Make sure the positive pin is in the positive slot and the negative pin to the negative slot.

Remember: The pin coming off the top of the battery is the positive and the pin coming off the bottom is the negative.

Side note: I’m using the battery Cr2032-2-15 button battery and the tabs aren’t 100% going to fit into the slots. I had to slightly modify the pins with diagonal cutting pliers so the leads can fit into the slots better. Hindsight has shown me that the CR2032-2H batteries with flat tabs would probably work better. I’ll have to test this theory out at a later date. You can purchase them here for $2.50 each.

Update: The Cr2032-T is the battery to use and from now on it will be the only that I will use for my games.It fits perfectly and looks stylish too.

With the battery in place, apply heat to the pin and then put the solder onto the board. The heat from the pin will melt the solder in place, securing the battery pin in place. Once you have enough solder on the PCB, quickly remove heat and gently blow to cool off your new connection. Avoid moving the battery during the cooling process to avoid cold solder joints. If you are having a difficult time with this process, temporally tape the battery in place so the battery won’t move during the soldering process. This should make the process easier. Repeat for the other pin.

Step 5: Once the battery is connected, remove the tape. Insert the PCB in the casing and assemble. If the battery is installed properly, the case should fit with no problems.

Side note:I had to break off a tab inside the game casing because my battery wasn’t exactly square to the old battery position. (see picture below) The battery was blocking the sleeve that went over the inside casing peg. To remedy this problem, I cut off the sleeve with my side cutters. Now it works 100%. A minor problem that could have been remedied by unsoldering and resoldering the battery is the right position. I was lazy and took the easy way out.

Step 6: Test your game and verify that it powers up. If it doesn’t work, double check your soldering and make sure that you don’t have a crossed connection. Play long enough to test your new battery by placing a save onto the cart. I usually wait a couple of hours and power up the cart again. Rattle your cart and verify that nothing is moving. Your game should still be there.

Congratulations: You just swapped out your game-saving battery. Enjoy your game for another 10-20 more years!

–Jangofatt